free software for illumination

Frequently Asked Questions

Which number format have I to use in dialogs?

Please use standard number format using a dot as decimal separator (not a comma). Some possible numbers: 0.20, 35, 1.5e2, 2e-2

Font used by the program is too small for me. What can I do?

Go to the menu 'Options/Font' and select a larger font. In the case that texts in dialogs overlap with entry-fields, you can eventually increase the Zoom-parameter in Options/Zoom menu.

I'm using wide screen and displayed plots are deformed. Can be aspect ratio of the plots set permanently?

After the plot is displayed, use your mouse to change the dimensions of the window until the plot is undeformed. Then click the left top corner of the GNUplot's window to activate GNUplot's menu. Select 'Options' / 'Update...wgnuplot.ini' menu and GNUplot will save current dimensions of the window and will use them in the future.

Why the displayed number of isolines is different than entered one in Graph option dialog?

In automatic-mode (only the number of isolines is entered), the isolines are distributed logarithmically and the same number of isolines is diplayed inside any decade. This implies that it is usually impossible to add one single isoline into the plot. When the entered number of isolines is increasing, the number of isolines shown in the plot increases stepwise. If you want to display exact number of isolines, enter their values into 'Isolines values'-field in 'Results/Graph settings' menu.

How can I change the number of decimal places displayed in the legend?

Please use 'Custom GNUplot commands' in 'Results/Graph settings' menu. Add a line containing text:
set clabel '%.2f'
where '2' means that 2 decimal places are displayed. '%.0f' displays numbers with no decimal places.

How can I change the position of the legend in the plot?

Please use 'Custom GNUplot commands' in 'Resutls/Graph settings' menu. Add one from following lines:
set key bmargin     - legend will be placed on the bottom
set key rmargin      - legend will be placed on the right
or add folowing line:
set key at x,y,1       - legend will be placed on the position [x,y] in room coordinate system

Can I turn the legend off? I want to write the legend manually in the figure caption.

Please use 'Custom GNUplot commands' in 'Resutls/Graph settings' menu. Add following line:
unset key

How can I obtain those nice plots presented on this page? Plots displayed on the screen looks whorse.

Good-looking plots can be obtained using GNUplots export functionality. Please use 'Custom GNUplot commands' in 'Resutls/Graph settings' menu:
1. Press 'Load' button and select one of prepared export filters. Their names are intuitive, GIF_Full_Colour.gpl will produce full-coloured GIF picture and so on.
2. Display any plot you want. Beside its displaying on the screen, corresponding picture is written to the disc.
Export commands are very simple. It will be no problem for you to change the picture resolution, font type and size, linewith, picture filename and other parameters of pictures written to disc.

It can be seen that somtimes isolines are projected outside the tube-area in tube-illumination plot. Why?

We use some smoothing on calculated data at their visualization (algorithm embeded into GNUplot). In the case that at the interface border a highly illuminated area occurs, the smoothing-algorithm results in spreading of the "illumination" outside the tube. The solution is simple: set your own isolines values (in 'Results / Graph settings' menu) excluding very low illumination values.

Can you suggest a colour palette which can be printed also in grayscale?

There are many GNUplot palettes which are good looking also in greyscale. Our favourite is "palette rgbformulae 8,9,10" (blue to yellow), which, when printed in grayscale, looks nearly as follows (click the picture to view full-resolution image):

This palette is useable for printing in scientific papers (their colour version is published on-line and grayscale version is published in paper form). We suggest also to change the font-size to 20 and the linewith to 2. Such figures can be scaled down to one-column width.
You can download in such a way optimized WMF_colour_grayscale.gpt file, which you can use in HOLIGILM program (see "Custom GNUplot Commands"). The WMF picture obtained you can convert into another format (e.g. TIFF) using any converter, e.g. IrfanView.

Is it possible to scale luminous intensity plot? Luminous intensity solid looks too small in some cases.

Please use 'Custom GNUplot command':
set view 'theta','phi','scale','scale-z'
set 130,0,1.5,1
where 'theta' is the position of the z-axis (0 deg = God's view, 180 deg = view from the workplane and 90 deg = side view), 'phi' is the rotation around z-axis, 'scale' is the overal scaling factor of the luminous intensity solid and 'scale-z' is scaling factor of the z-axis.

Image samples created using 'set view 130,0,1,1' (left) and 'set view 130,0,1.6,1' (right)

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