IDL Tutorial 2: Plots and Output Files for Making Hardcopies .. Hence, you need to first start the PS device using the set_plot command, and then use the. SET_PLOT, ‘PS’. This causes IDL to use the PostScript driver for producing graphical output. Once the PostScript driver is enabled via SET_PLOT, the DEVICE. IDL treats the screen as one device and a postscript file (which you can print) as another. You can switch devices with the set_plot command.
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To direct graphics output to a PostScript file, issue the command: This procedure reads an X Windows Dump file and writes it back out as a properly-sized, 8-bit-color Encapsulated PostScript file: To put multiple plots on the same PostScript page, use the!
Any routines that rely on data coordinates should not be called until a new data coordinate system has been established. Assuming that the previously-selected device’s color table contains M elements, and the new device’s color table contains N elements, then the minimum of M and N elements are loaded. This is easily done with the statement:. Sample PostScript plot using Helvetica font. Set this keyword to copy the device’s color table from the internal color table, preserving the current color mapping.
You have more options under Linux, but your best bet is to use a program called “gv. This make automatic set_plkt of PDF files problematic. Run your plotting script. Many laser printers and high-resolution, high-quality photo typesetters support PostScript. First, make a script to generate a plot on the graphics window.
As with most display devices, color indices range from 0 to Similarly, when output to an EPS file, this image will only fill a small portion of the bounding box. The default is to do nothing. It also provides several examples of how the PostScript graphics device is used. It sets the default color! PostScript is a programming language designed to convey a description of a page containing text and graphics.
Use of PostScript fonts is discussed in detail in. Text and graphic color indices are translated to RGB by dividing the red, green and blue color table values by Because devices have differing capabilities and not all are capable of representing the same number of colors, the treatment of color tables when switching devices is somewhat tricky.
IDL Graphics Devices
Polygon Filling Example illustrates polygon filling. For example, the following lines of code create a PostScript file, multi.
The width of the seet_plot in pixels is stored in s. True-Color Images A true-color image consists of an array with three dimensions, one of which has a size of three, containing the three color components. Such graphics output compares favorably with the output from IDL 8 function graphics commands, although Coyote Graphics output files are generally smaller in size.
IDL Tutorial: Generating Hardcopy of Plots
You can also view the file in a blank Word document. Unlike monitors where white is the most visible color, PostScript writes black on white paper. Pseudo-color images are similar to those displayed using the workstation monitor.
Drawing text or graphics with a color index of 0 results in black, 1 in red, 2 in green, and 3 in blue. Isn’t there some way to do this directly from within IDL!? A scalar string containing the name of the device to use.
Department of Physics and Astronomy. For the histogram plot, for example, you can now just type this.
The PostScript Device
The case of Device is ignored by IDL. In addition, images are either pseudo-color or true-color. A pseudo-color image is a two dimensional image, each pixel of which is used to index the color table, thereby obtaining an RGB value for each possible pixel value.
This offset is also taken relative to the lower left-hand corner of the page when set_plog in portrait orientation. D to reflect the configuration of the new device.
IDL Tutorial 2 : Plots and Output Files for Making Hardcopies
Then, use a postscript viewer to look at it and print it, or, if one is not available, embed the plot in a word processing document. If the image column size is not an exact multiple, extra pixels with a value of are output at the end of each row.
Here, the X and Y offsets are still taken relative to the same points even though the orientation of the plot has changed. Note that if you have Adobe Acrobat, you can also use the Adobe PDF printer that is installed with Acrobat to accomplish the same thing.
MULTI system variable described in more detail in. In each case, a different number of bits are used per image pixel. Back to Index Next Tutorial. Set this keyword to indicate that the current contents of the internal color table should be interpolated to cover the range of the newly-selected device.
Be careful when switching devices as the number of color indices frequently differs between devices. Set up IDL to plot an encapsulated postscript file of some chosen name.
The page on the right shows an IDL plot printed in “landscape” orientation. The Macintosh computer uses the built-in pstopdf program to do the conversion for you.