# The Dialogs

# Add Custom Action

This dialog helps you define new Python script launchers that will be added to menus or tool bars in QtiPlot. You can fully customize the script launchers by defining: a textual description that will be displayed in the destination menu, an icon, a shortcut key sequence and a tool tip. The Tool Tip Text is a short description that will be displayed near the launcher button when you hover the mouse over it. You can only assign unique shortcut key sequences to your custom launchers.

## The &add-custom-action-cmd; dialog box.

The Script File is the path to the Python script that will be executed when you click the launcher. When you click the Add button all the settings for the new launcher are saved to an XML file in the directory specified in the Folder box. On start-up QtiPlot parses all XML files in this folder and creates the corresponding menu items or toolbar buttons. When you press the Remove button, the launcher selected in the left side list of the dialog is removed from QtiPlot menus/tool bars and the corresponding XML file is deleted from the hard disk.

# Add Error bars

This dialog is activated by selecting the &add-error-bars-lnk; from the &graph-menu-lnk;.

This command is used to plot X and/or Y error bars around the data points.

It must be taken care that the "add" button add the errors bars, and so do the "OK" button. Then, you should close the dialog with cancel if you have clicked on the "add" button.

## The &add-error-bars-cmd; dialog.

There are three ways to specify the size of the bar:

A column of the table

  In this case, the values of the selected column are used to compute the error bars. if V is the value of the data point, and E the value of the errorbar column, the size of the bars will be V-E to V+E.

A percentage of the values

  if E is the percentage selected, the size of the bars will be V(1-E/100) to V(1+E/100). It must be noticed that, in addition to the errorbars on the plot, this command will create a new column in the active table with can be used in the way as with the previous option. This column can be modified like any other one.

The standard deviation of the values

  the standard deviation of the values. This has a meaning only of the data are centered around an average value. Like with the previous option, a new column will be created in the active table.

## A plot with X and Y Error Bars.

# Add Function

This dialog box is used to add a function curve to the active plot. The function can be built with the common operators: * + / - and ^ for the power. The intrinsic functions available are listed in the appendix.

The most common way to define a function is the classical cartesian coordinate definition y=f(x), this is the defaut option. The two following parameters allow to select the x range used for the plot, and the last one is used for the number of data points that are computed in the X-range.

## The &add-function-cmd; dialog box: cartesian coordinates.

The functions can also be defined in a parametric definition: if t is the parameter, the (x,y) data points are computed by x=f(t) and y=g(t).

The first parameter is the name of the parametric variable (here t) followed by the range, the definition of the two functions and the number of data points.

## The &add-function-cmd; dialog box: parametric coordinates.

The last way is the polar definition of the function: if t is the parameter, the radius r and the angle theta are computed by r=f(t) and theta=g(t). Then the (x,y) data points are computed by x=r*cos(theta) and y=r*sin(theta).

The first parameter is the name of the parametric variable (here t) followed by the range, the definition of the two functions and the number of data points.The angle is defined in radians, and the constant value pi can be used: it is possible to use 3*pi to define the parameter range.

## The &add-function-cmd; dialog box: polar coordinates.

# Add Layer

This dialog is opened when you want to add a new layer on the active plot. If you select Guess, &appname; will divide the window in two columns and put the new layer on the right. If you choose Top-Left Corner, &appname; will create a new layer with the maximum possible size over the existing layer, this layer contains an empty plot. You can then modify the size and position of each layer by selecting it with the layer number buttons and selecting the Layer Geometry command from the context menu.

## The &add-layer-cmd; dialog box.

# Add/Remove curves

This dialog is activated by selecting the command &add-remove-curve-cmd; from the Graph Menu.

The left window shows the columns which are available for plotting in the different tables of the project. If the Show current folder only option is checked, only the tables in the active folder of the project will be listed in this window. The right window gives the list of the curves already plotted. In the case presented below, there are two tables from which the &add-remove-curve-cmd; dialog box allows to select columns. If you use this dialog box to add a column, the X column will be the one defined as X in the corresponding table.

## The &add-remove-curve-cmd; dialog box.

In this dialog box, if you select one curve of the plot in the right window, you can change the columns used for X and Y with the Plot Association button. In any case, you can't mix the X values of one table with the Y values of another one. If you want to do this, you have to copy the columns in the same table.

If the curve selected is a function, you can modify it by pressing the Edit Function... button. Refer to the &add-function-cmd; dialog box for more details on functions editing.

If the Show Range option is checked, the plot range of all the curves not defined as analytical functions will be also displayed in the right window of the dialog. The plot range is the interval of points which are visible in a curve. You can show/hide data points from a selected curve, without having to delete them, by pressing the Edit Range... button, which opens a dialog allowing to edit the plot range.

# Arrange Layers

This dialog is activated by selecting the command &arrange-layers-cmd; from the Graph Menu or by the key code &arrange-layers-key;.

It allows to modify the geometrical arrangement of the plots which are already present in the active window. You can add new layers or remove existing ones using the Number of layers control. You can specify the numbers of rows and columns which will define a grid of plots. With the default settings, &appname; computes the size of the layers from the size of the window. If you check the Layer Canvas Size, you can set the size of the layers and &appname; will modify the size of the window.

The controls in the two right group boxes, Alignment and Spacing, allow to set the alignment of the layers in the window, and the margins between the layer borders and the window limits. Finally you have the possibility to swap two layers using the Swap Layers box.

## The &arrange-layers-cmd; dialog: the geometry tab

The layers will be arranged in order to obtain a good alignment of the vertical and horizontal axis.

## Exemple of a vertical arrangement for two plots.

If you do some modifications on your plot, the alignment of the different axis may not be conserved. You can exec again the &arrange-layers-cmd; to re-arrange your plot.

# Line Options

This dialog allows to modify a line or an arrow which has been created by the command &draw-arrow-cmd; from the Graph Menu or with &draw-arrow-key;. One can also open it with a double click on an arrow or a line, or by selecting an arrow or a line and selecting Properties... with the right button of the mouse.

The first tab allows to change the color, the line type and the line width. This last parameter is set in pixels. It is possible to define a default style for all the new lines by pressing the Set Default button.

## The Arrow options dialog: first tab

The Arrow head tab is used to modify the shape of the head of the arrow. The length is set in pixels and the angle is in degrees. It is also possible to define a default style for the arrow heads using the same Set Default button.

## The Arrow options dialog: second tab

The Geometry tab allows to specify the start and end points of the line/arrow. The coordinates can be set as a function of the scales values displayed on the left axis (Y) and on the bottom axis (X) or in pixels, by choosing the desired method from the Unit pull-down list. The pixel coordinates are relative to the top-left corner of the layer which contains the line.

## The Geometry dialog: third tab

# Column Options

This dialog is activated by selecting the command &column-options-cmd; from the Table Menu. At least one column must be selected.

## The &column-options-cmd; dialog.

The checkbox Enumerate all to the right can be used to build the name of all the columns which are at the right of the selected one. If the name of the selected column is "xyz", this column and the following ones will be renamed to "xyz1", "xyz2", and so on.

The buttons "<<" and ">>" are used to change the selected column. The highlighting of the column in the table behind the dialog box will change indicating that a new column was selected. The column to which the formatting commands are applied is the one whose name appear in the "Column Name" box.

The Plot Designation selector is used to define the columns which are used as X, Y or Z values or as error bars. In a table you can select several columns as X, in this case in the column label they will be indicated as [X1], [X2], etc... and their corresponding Y columns will be indicated as [Y1], [Y2], etc...

The Comment box allows to enter a text that can be displayed in the table header under the column name, if the option Display Comments in Header is checked.

# Contour Curves Options

This dialog is activated by clicking on a contour curve (or on the plotting area) when a 3D plot has been created from a matrix with one of the following commands of the &plot3d-menu-lnk;: &contour-color-lnk;, &contour-lines-lnk; or &gray-scale-lnk;.

## The Contour Options dialog.

The first group of settings Image is checked if you want to have a color or gray level filling of the contour plot. The default gray and color maps are the following:

You can customize this colormap by checking the Custom Colors box. A table with a set of numbers (the Z levels) and the corresponding colors is presented. You can then add or delete new levels for the definition of the colormap, and modify the corresponding Z levels. You are not allowed to modify the first and last levels, which are set to the minimum and maximum Z values. Beware that this is only the definition of the colormap, it won't change the number of contour lines of your plot. An example of classical custom colormap is given here:

If you want to obtain discrete colors for each level,you must uncheck the Scale Colors checkbox. In this case you must define enough levels in your colormap.

The second group of settings is used to customize the contour lines. You can select the number of lines and their color. If you check Use Default Pen, the color of the line will follow the settings defined in the group at the left of the checkbox. If you check Use Color Map, the lines will be colored as a function of the Z levels following the colormap defined in the image setting group.

The last group of settings must be checked if you want to have a bar scale on your plot. You can then define its position and width.

# Plot Details

This dialog is activated by selecting the command &format-plot-cmd; from the Format Menu. It is also activated by a double click on the plot. If there are more than one layer in the window, &appname; will select the layer which contain the plot under the mouse pointer.

## The Plot Details Dialog: Layer properties.

The second tab defines the geometry of the plot layer.

## The Plot Details Dialog: Layer geometry.

The right part of the dialog box contains several tabs which depend on the kind of plot that you are using, they are described in the following subsections. The left part of the dialog window shows the curves which are plotted in the active layer. All the modifications will be done on the selected curve. You can change the columns which are used by clicking on the Plot Associations... button. This will open a dialog which can be used to select the columns of the table which are used as X and Y values.

## The Plot Details Dialog: Plot Associations.

The button Worksheet can be used to access to the table which contains the columns selected.

## Custom curves for lines and scatter plots

The first tab of the right part of the dialog window allows to define the pair of axes to which the curve is attached. You can thus represent different curves having different x/y scales on the same plot layer.

### The Plot Details Dialog: assign axes.

The second tab of the right part of the dialog window allows to modify the style of the line (color, line style, thickness). The connect button allows to change the style which is used to draw the selected curve (steps, droplines, etc). See the &plot-menu-lnk; to see the different types of plot available.

### The Plot Details Dialog: Line formatting.

A third tab can be activated to select the symbol, and to modify the size, the color and the filling color of the symbols.

### The Plot Details Dialog: Symbol formatting.

The Labels tab can be used to define labels to be plotted for each data point in the plot and to modify the font, the color, the rotation angle and the position of the labels.

### The Plot Details Dialog: Labels formatting.

## Plot Details for pie plots

These commands are available for pie plots. The first tab allows the customization of the pie segments. The left fields are used to modify the border which is drawn round each segment: color, type and width of line. The default is no border (line width = 0).

The right fields are used to define the filling of the plots. The color button defines the one used for the first segment, then the others segments will have colors which follow the order defined in the list. The default value for this field is black, so segment 2, 3, etc will be red, green, etc.

The pattern will be used for all segments of the pie, the default value is solid filling.

### The Plot Details Dialog for pies: pie segment formatting.

### The Plot Details Dialog for pies: pie geometry.

### The Plot Details Dialog for pies: pie labels formatting.

## Custom curves for box plots

### The Plot Details Dialog for box: pattern formatting.

### The Plot Details Dialog for box: whiskers formatting.

### The Plot Details Dialog for box: percentile formatting.

## Custom curves for pie histogram

### The Plot Details Dialog for histogram: pattern formatting.

### The Plot Details Dialog for histogram: spacing formatting.

### The Plot Details Dialog for histogram: data formatting.

# Define surface plot

This dialog is used when you enter the &new-surface-3d-plot-cmd; command. It allows to create a new function of two variables. The only available coordinate system is the cartesian one: z = f(x,y).

## The &new-surface-3d-plot-cmd; dialog box.

You can then enter the X, Y and Z scales and you can define the mesh parameters.

You can also create parametric surfaces. The only parameters allowed are the latitude and the longitude: `u` and `v`. Here's, for example, how you can plot a sphere having a radius equal to one:

## The &new-surface-3d-plot-cmd; dialog box.

Like in the case of functions, you can supply the drawing domain for the two angle parameters and you can define the mesh parameters. The more rows/columns you request for, the better the resolution of the output image, but also the larger the memory consumption and the lower the speed of your computer.

Also, you can provide information about the rotational symmetry of the parametric surface to the drawing routines, using the two `Periodic` box options (one for each parameter).

# Export ASCII

This dialog is activated by selecting the command &export-ascii-cmd; from the File Menu. The command is active if there is at least a table window in the project.

This command is used to export all or a part of the data of a project in an ASCII file.

## Export of a selection in a table to an ASCII file.

In this example of export of a table selection to an ASCII file, the names of the selected columns are exported as the first line of the file. The comments displayed in the table header are exported as the second line of the file and a TAB character is used as a separator between the columns. Only the two selected columns are exported.

If the "Include Column Names" option is not checked, the names of the columns will be set to C1, C2,... in the exported file. The formatting of the numbers is kept in the ASCII file, so you have to be careful to obtain a good enough precision in the ASCII file.

# Add/Remove curves

This dialog is activated by selecting the command &add-remove-curve-cmd; from the Graph Menu.

The left window shows the columns which are available for plotting in the different tables of the project. If the Show current folder only option is checked, only the tables in the active folder of the project will be listed in this window. The right window gives the list of the curves already plotted. In the case presented below, there are two tables from which the &add-remove-curve-cmd; dialog box allows to select columns. If you use this dialog box to add a column, the X column will be the one defined as X in the corresponding table.

## The &add-remove-curve-cmd; dialog box.

In this dialog box, if you select one curve of the plot in the right window, you can change the columns used for X and Y with the Plot Association button. In any case, you can't mix the X values of one table with the Y values of another one. If you want to do this, you have to copy the columns in the same table.

If the curve selected is a function, you can modify it by pressing the Edit Function... button. Refer to the &add-function-cmd; dialog box for more details on functions editing.

If the Show Range option is checked, the plot range of all the curves not defined as analytical functions will be also displayed in the right window of the dialog. The plot range is the interval of points which are visible in a curve. You can show/hide data points from a selected curve, without having to delete them, by pressing the Edit Range... button, which opens a dialog allowing to edit the plot range.

# Fast Fourier Transform

The &fft-cmd; dialog box can be used either on a table or on a plot. It is used to compute a direct or inverse FFT. See the FFT section in the Analysis chapter for an example.

## The &fft-cmd; dialog box for a curve.

&appname; will create a new plot window with the FFT amplitude curve, and a new table which contains the real part, the imaginary part, the amplitude, and the angle of the FFT.

If the Normalize Amplitude check box is on, the amplitude curve is normalized to 1. If the Shift Results check box is on, the frequencies are shifted in order to obtain a centered x-scale.

## The &fft-cmd; dialog box for a table.

In the case of a table, you must select the sampling column (X-values) and two columns for Y-values. If they are complex numbers, the first column is the real part of Y-values and the second is the imaginary part. If Y-values are simple reals, you don't have to select a column for the imaginary part, you can leave the combo box empty.

By default, the Sampling Interval corresponds to the interval between X-values. Giving a smaller value makes no sense, but you can increase this value in order to sample less values

# Integrate dialog

This dialog box is opened if you select the &integrate-cmd; command from the &analysis-menu-lnk; The first field is the curve that will be integrated. The second one is the order of the integration: the order 1 corresponds to the trapezoid rule, i.e. the curve is aproximated by a straight line between 2 successive points. If you choose the order 2, three successive points are used and a second order polynome is used to approximate the curve. etc. If you have a large amount of points in your curve, the order 1 is enough.

## The &integrate-cmd; dialog box.

The result of the integration will be given in the The Project Explorer.

# The Fit Wizard

This dialog is activated by selecting the command &non-linear-curve-fit-cmd; from the Analysis Menu. This command is active if a plot or a table window is selected. In the latter case, this command first creates a new plot window using the list of selected columns in the table.

This dialog is used to fit discrete data points with a mathematical function. The fitting is done by minimizing the least square difference between the data points and the Y values of the function.

## Note:

If the data points are modified, the fit is not re-calculated. Then, you need to remove the old fitted curve and to redo the fit with the same function and the new points.

The top of the dialog box is used to choose a function among the one which are already define. Four types of functions are availables: the user defined functions which have been saved, the classical functions proposed by &appname; in the analysis menu, the simple elementary built-in functions, and external functions via pluggins.

To choose one of these functions, you just have to select it and to click on the checkbox under the selector.

If you want to define your own function, you can use the bottom half of the dialog box. You can write you own mathematical expression or add expressions obtained with the function selector. Then you need to define the parameters which have to be fitted in a comma separated list.

## The first step of the &non-linear-curve-fit-cmd; dialog box.

This first step is used to define the function which will be used for the fitting

The second step is to define the parameters for the fit. You have to give initial guess for the fitting parameters.

## The second step of the &non-linear-curve-fit-cmd; dialog box.

This second step is used to define the parameters of the fitting

In this second tab you can also choose a weighting method for your fit (the default is No weighting). The available weighting methods are:

1. Instrumental: the values of the associated error bars are used as weighting coeficients. You must add Y-error bars to the analysed curve before performing the fit.

2. Statistical: the weighting coeficients are calculated as the square-roots of each data point in the fitted curve.

3. Arbitrary Dataset: you have the possibility to set the weighting coeficients using an arbitrary data set. The column used for the weighting must have a number of rows equal to the number of points in the fitted curve.

After the fit, the log window is opened to show the results of the fitting process.

Depending on the settings in the Custom Output tab, a function curve (option Uniform X Function) or a new table (if you choose the option Same X as Fitting Data) will be created for each fit. The new table includes all the X and Y values used to compute and to plot the fitted function and is hidden by default, but it can be found and viewed with the project explorer.

## The third step of the &non-linear-curve-fit-cmd; dialog box.

This third step is used to customize the output of a fitting operation.

This dialog tab provides controls that can be used to evaluate the goodness of fit. The first one is the Residuals Plot button which can be used to display the curve of the plot residuals. The Conf. Bands and Pred. Bands buttons can be used to generate confidence and prediction limits for the current fit, based on the user input confidence value.

After the fit, a series of fit statistics are displayed in the log window allowing to evaluate the goodness of fit. This values are:

1. Chi^2/doF
2. R-square
3. Adjusted R-square
4. RMSE (Root Mean Squared Error)
5. RSS (Residual Sum of Squares)

For detailed explanations about the meaning of this statistical values, please visit the following link.

By default, the reported errors are not automatically scaled with the square root of the reduced chi-squared value. You can choose to enable this option by checking the Scale errors with sqrt(Chi^2/doF) box.

# General Plot Options

The first tab is used to set the general scales used for the two or three axis.

## General plot options dialog: the scale tab.

In this tab, you can also set the number of ticks used for each axis. This can be done in two ways: you can set the number of labels which are used for the whole scale. Whatever the number you enter, &appname; will use a value which leads to a pretty plot: for example, if you enter 7 ticks for a 0..100 scale, &appname; will use 10 major ticks from 10 to 10. If you want to fix non classical values, you can select the step method.

The grid tab is used to draw grid lines on the plot. The frequency of the lines are related to the number of label and major ticks set with the Scale tab.

## General plot options dialog: the grid tab.

The third tab is used to modify the setting of the different axis. You must select the axis that must be customized in the right window. The label of the axis can be modified in the title window, see the text options dialog section for more details.

## General plot options dialog: the axis tab.

The General settings tab is used to customize the global aspect of the plot. The canvas is the area defined by the axis, you can draw a box around this canvas and define a background color for this canvas. The background area is the global drawing area, you can also define a color border and a background color for this area. The margin parameter controls the distance between the drawing area limit and the canvas. If you want to modify the margin between the window limits and the drawing area, you must modify the layer parameters (manualy with the mouse or with the arrange layers dialog.

## General plot options dialog: General settings.

The parameters in the Axes group allow to modify the linestyle of the axes and of the ticks.

# Plot Wizard

This dialog is activated by selecting the command &plot-wizard-cmd; from the View Menu or with the &plot-wizard-key; key. This command is always active.

This dialog is used to build a new plot by selecting the columns in the tables available in the current project. At first, you have to select the table you want to use, and then click on New curve to create the curve. After that, you have to select at least one column for X and one for Y. You can also select one more column for X-errors or for Y-errors. The plot created will have the default style you defined using the Preferences dialog through the '2D Plots -> Curves' tab.

## The plot wizard dialog box.

In this example, one curve is selected from the first table, and the other from the second table (with X error bars)

# Project Explorer

The project explorer shows a list of all the windows, tables, matrices and folders which are included in the current project. It can be used to create new folders and windows, to find existing ones, to make hidden elements visible, to perform basic operations like: renaming, deleting, hiding, resizing, printing, etc... You can also use it in order to display the list of dependencies and properties of an element in the project.

## The project explorer panel.

# Preferences Dialog

The preference dialog is used to customize the application. It has six different tabs. If you confirm your changes to the default behaviour of the application, the changes are saved and stored imediatelly.

The first icon can be selected to change the General options of the application. In the first tab: Application, the style is the general decoration used for the windows. It defines the aspect of the buttons and dialog boxes. The available styles are part of the Qt library. The font is the general font used for the GUI (menus, dialogs, etc), it doesn't apply to the plots. You can select the language of the application in the corresponding combo-box. All translations available can be downloaded from the following address: http://soft.proindependent.com/translations.html. By default the translations must be place in a folder called translations, situated in the same location as the &appname; executable, in order to be loaded by the application, but you can specify a different folder via the File Locations tab.

## The preferences dialog: general parameters for the application.

The Matrix Undo Stack Size is the number of operations that can be undone/redone when working on a matrix. By default it is set to ten operations. A high value for this parameter can be very costly in terms of memory consumption, especially for large matrices.

The Endline character defines the end of line convention used by &appname; for copy/paste operations and for exporting matrices/tables to ASCII files. The end of line convention can be: Line Feed (LF), Carriage Return + Line Feed (CRLF) or Carriage Return (CR) only.

Starting with version 0.9.6, autocompletion is enabled by default in all QtiPlot editors: in Notes, in the Script Window and in the values dialogs for matrices and tables. The autocompletion mechanism is based on a list of words provided by the qti_wordlist.txt file. This file, which is shipped with the source archive, must be placed in the same folder as the Python configuration files (see File Locations tab bellow), and is automatically loaded by QtiPlot on start-up. You can edit this file and add your own key words: one word per line.

Completion suggestions are automatically poped-up for words that have more than two characters, but you can trigger autocompletion at any time using the shortcut Ctrl+U. Autocompletion can be disabled by unchecking the Enable autocompletion option.

The second tab of the General option set is used to disable the prompting on deleting project windows. Also you can disable the warnings prompted by default when renaming new table windows with names already used in the current project.

In this tab, you can change the default color for the workspace of the application. You can also choose the background color and the text color for panels. The panels are the Log Window and the Project explorer.

The Numeric Format tab allows you to customize the characters used as decimal point and as thousands separator. By default, &appname; uses the locale settings detected on your system. If the Update separators in Tables/Matrices is checked, &appname; will try to convert all the existing data in your project to these new settings when you click the Apply button. The Number of Decimal Digits specifies the default precision used for any calculations operated on your data in Tables/Matrices.

The File Locations tab allows you to define custom locations for the folders containing the translation files, the manual files and the Python configuration files, qtiplotrc.py and qtiUtil.py, in case &appname; was built with Python scripting support.

The second set of option allows to customize the defaut aspect of tables: background, text colors, and fonts for tables and labels. By checking the Display Comments in Header option, the column comments will also be displayed in the table header, bellow the column names. If the Automatically Recalculate Column Values option is checked, all modifications in the values of a column trigger a recalculation of all columns with formulas depending on the modified column.

## The preferences dialog: table options.

The second set of options is used to customize the default aspect of 2D plots. The first tab is used to modify some general options. Most of the changes made to these options will be applied only to the newly created plots. Only a few of the changes, like Autoscaling of the plot axes, Antialising of curves and the behavior on resize events will also affect the already existing plots.

## The preferences dialog: 2D plot options.

The second tab named Curves defines the default style used when you create a new plot.

The third tab named Ticks defines the default style for the ticks of the axes used when you create a new plot.

The fourth tab named Fonts defines the default fonts used when you create a new plot.

The fifth tab named Print allows you to define the default options used when printing 2D plots. If you want the layers to be printed with their original dimensions, you must be sure to uncheck the option Scale layers to paper size. By checking the Print Cropmarks option you ensure that some visible marks are drawn around the borders of the plot.

The following tab allows to customize the aspect of three dimensional plots. From this dialog you have the possibility to define a speed drawing mode, which is very usefull when working with large data sets. This can be realized via the Resolution option: the higher this value, the smaller the number of data points drawn on the 3D plots, therefore the higher the drawing speed. For a value of 1, all the data points are drawn.

## The preferences dialog: 3D plot options.

## The preferences dialog: fitting options.

# Printer-setup

This dialog box is opened by the &print-lnk; from the &file-menu-lnk;. It is used to print the selected window (plot or table) and its aspect depends on your operating system. The following screenshot shows this dialog on a Linux system using the KDE window manager.

## The &print-cmd; dialog.

# Set Column Values

This dialog is activated by the &set-column-values-lnk; of the &table-menu-lnk;. It allows to fill a column with the result of a function.

The available mathematical functions (assuming you are using the default scripting language, muParser) are listed in the appendix. The special function col(x) can be used to access to the values of the column x, where x can be the column's number (as in col(2)) or its name in doublequotes (as in col("time")). You can also get values from other tables using the function tablecol(t,c), where t is the table's name in doublequotes and c is the column's number or name in doublequotes (example: tablecol("Table1","time")).

The variables `i` and `j` can be used to access the current row and column numbers. Similarly, `sr` and `er` represent the selected start and end row, respectively.

Using Python as scripting language gives you even more possibilities, since you can not only use arbitrary Python code in the function body, but also access other objects within your project. For details, see here.

Nevertheless, even if Python allows for a more powerfull synthax, it can be quite slow for very large tables. Therefore you have the possibility to use muParser instead, even if Python is set as the default script engine for your current project, by checking the box Use built-in muParser. Using muParser as scripting engine higly increases the speed of the evaluation for single line expressions.

## The &set-column-values-cmd; dialog.

Warning: If you make some changes in the table, the values are not computed again. You have to explicitly tell QtiPlot to recalculate individual cells or whole columns or rows by selecting "Recalculate" from their context menu or by pressing Control+Return.

# Set Matrix Dimensions

This command is in the &matrix-menu-lnk;. It allows to specify the number of rows and columns of a matrix. In this window, you can also define a range for X-values and Y-values. These X and Y ranges will be used in plots as initial scale ranges. They are also available via the x and y variables if you choose to define the content of the matrix with the Set Values Dialog.

## The &set-dimensions-cmd; dialog for matrix.

# Import ASCII files

This dialog is activated by selecting the command &import-ascii-cmd; from the File Menu. It can be used to select several files at a time. The files are imported using a set of default options. You can display and edit these options by pressing the Advanced button. All your changes to the default import parameters will be saved.

## The dialog box.

If you want to import several data files, the first parameter Import each file as must be set to "New Table".

Concerning the separator which is used between the columns, you must bear in mind that there is no grouping of separators, so if you use "SPACE", you must use only one separator between each column or check the Simplify white spaces option.

If your data files have a particular structure, for example if they present several lines containing the description of your experiment, before the actual data start, you have the possibility to skip the n first lines of the file. You can also skip all lines starting with a comment character/string. The comment string can be customized via the text edit line Ignore lines starting with.

If you choose to use the first line as column names and/or the second line as comments to be displayed in the table header, you must use the same separator between the column names and between the data columns.

Finally, assuming that the data files you want to import were created using different decimal separator conventions than the ones you're using, like for example a comma character for the decimal point instead of a dot character, you have the possibility to convert the data to your current settings, by checking the Import decimal separators option and by specifying the Decimal Separators convention used in the ASCII files.

# Matrix Properties

This command is in the &matrix-menu-lnk;. It allows to specify some global properties of the selected matrix such as the cell width (in pixels) and the format for numbers.

## The &set-properties-cmd; dialog for matrix.

# Set Matrix Values

This command is in the &matrix-menu-lnk;. It allows to fill in a matrix with the results of a function z=f(i,j) in which i and j are the row and column numbers.

You can use the X-values and Y-values defined with the &set-dimensions-lnk; command, and also define your functions based on the x and y variables.

The functions can be written on several lines, and the intrinsic functions which are available are listed in the appendix .

## The &set-values-cmd; dialog for matrix.

Using Python as scripting engine for the calculation of matrix values has the drawback that even if it allows a more powerfull synthax, it can be quite slow for large matrices. Therefore you have the possibility to use muParser instead, even if Python is set as the default script engine for your QtiPlot project, by checking the box Use built-in muParser. Warning: muParser is very fast for the evaluation of single line expressions only, therefore try to avoid a synthax like:

        a = cell(1, 1)
        b = cell(2, 2)
        a*b*x + b*x*x + a

and prefer the following one:

        cell(1, 1)*cell(2, 2)*x + cell(2, 2)*x*x + cell(1, 1)

which will highly increase the speed of the evaluation!

# Surface plot options

This dialog box is used to customize a 3D function plot which has been created by the &new-surface-3d-plot-lnk; from the &file-menu-lnk;. It is activated by a double click on the 3D plot.

The first tab is used to modify the X, Y and Z ranges. It allows also to specify the number of labels on the axis and the number of secondary ticks.

## The surface plot options dialog box.

The second tab defines the main parameters of the three axis: the axis label and its font, and the length of the ticks. This length is defined in the same units as the range of the axis. If something is changed in the scales of the graph, the length of the ticks is re-calculated by &appname;. The font button allows to modify only the font used for the label, if you want to customize the font of the numbers used for the axis, you must used the fifth tab.

The third tab is used to define or modify the title of the plot. You can not add subscripts/superscripts, bold characters, etc in your title as you can do it for 2D plots.

The fourth tab allows to modify the colors used in the different elements of the plot.

The first set of two colors (data min and data max) defines the color scheme which is used to show the Z-values. They are the colors used for the minimum value of Z (Zmin) and the maximum value of Z (Zmax). We can define the colors by their Red, Green and Blue parameters: [R,G,B]. Then, a value Z will be represented by a color defined as a linear interpolation:

The default colors for Zmin and Zmax are respectively blue ( [R,G,B] = [0,0,255] ) and red ( [R,G,B] = [255,0,0] ). This lead to the following color scheme:

Another classical color scheme can be built with Zmin = [160,32,32] and Zmax = [255,255,0] (yellow). It leads to:

Another way to define colors is to read a colormap from a file. The format of the file is simple: each line defines a color by red, green and blue values as integers between 0 and 255. The numbers should be separated by spaces. You can find several examples of colormaps on the QwtPlot3D web site.

The last tab is used to define some global parameters and the aspect ratio of the plot. The default behaviour is to use the perspective to compute the 3D plot. If you choose to check the Orthogonal check box, the plot will use vertical Z axis whatever the view angle of the plot.

## The surface plot options dialog box with tab 5: aspect ratio.

# Text options

This dialog can be opened by several commands such as &format-title-lnk; or when you double click on an axis title in your plot. The Color, Font and Alignment commands allow the modification of the general settings of the text label. By checking the box Apply format to all labels in layer, the formating will be applied to all texts in the plot layer, including the plot title and the axes labels.

## The axis title options dialog.

The following slightly modified dialog is opened when you double click on texts/legends in your plot in order to customize them. It also allows to add text boxes to a plot layer. When the text object is a legend, listing the curves plotted on the layer, the curve symbols and lines are also drawn in the text box, in front of the curve names. In order to display the symbol of a curve and the name of the data set, the follwing synthax is used: \l(2)%(2). Here the number 2, refers to the index of the curve and the % character is an alias for the name of the data set.

The Opacity of the Background color can have a value between 0 (transparent background) and 255 (completely opaque background).

## The legend/text options dialog.

The text item can be modified in the text window. Several improvements can be added to the text:

- <sub>text</sub> will draw the text as subscripts. You can insert this sequence by clicking on the .

- <sup>text</sup> will draw the text as superscripts. You can insert this sequence by clicking on the .

- By clicking on the , you can open a new dialog which allows to select lower greek characters:

- By clicking on the , you can open a new dialog which allows to select upper greek characters:

- By clicking on the integral symbol you can open a new dialog which allows to select various mathematical symbols:

- By clicking on the arrow icon, you can open a new dialog which allows to select various arrow symbols:

- <b>text</b> will draw the text with bold characters. You can insert this sequence by clicking on the .

- <i>text</i> will draw the text with italic characters. You can insert this sequence by clicking on the .

- <u>text</u> will draw the text with underlined characters. You can insert this sequence by clicking on the .