Direct Graphics Display Tips

Line Plot Tips

• How do I create a graphic with a specified aspect ratio?
• How can I add a second, logarithmic axis to my plot?
• How can I create a plot with irregular tick spacing and values?
• How can I create a polar plot with axes through the center?
• I'm trying to do yada yada with log axes and it's not working. What am I doing wrong?
• I found the error bar routines in IDL, but can I plot error bars in the X direction, too?
• Is it possible to get the X axis labels on top of the plot instead of at the bottom?
• How do I fill the area under a curve with a color?
• Is there any way to change the text orientation of axis labels?
• Is there a way to plot the wave length on one axis and the corresponding wave number on another?
• I'd like to make a sort of stacked ladder plot. Can this be done in IDL?
• There is no room for a title on my plot. What can I do?
• I want to plot pressure on the Y axis, but I want the data range reversed. How do I do that?
• Is there a way to label minor tick marks on a logarithmic axis?
• Can you show me how to display a colored background inside my plot axes?
• How come my minor tick marks disappeared?
• Why does my sine plot look so lousy in IDL?
• Is there a way to draw a transparent polygon over my line plot?
• How can I include a grid on my line plot in IDL?
• How can I draw a multi-colored line in an IDL graphics plot?
• Can you show me how to draw a box and whisker plot in IDL?
• Instead of using symbols, can I use numbers to label my plot?
• Is there a good replacement for the Plot command?
• Is there a good replacement for the PlotS command?
• Is there a good replacement for the Oplot command?
• Yikes! Changing the X range of my plot affects the Y range. Is this a bug?
• Can you show me how to create an anisotropy pie plot in IDL?
• Can you show me how to create a 2D scatter plot.

Contour Plot Tips

• How do I contour irregular data on a map projection?
• There is a hole in my filled contour plot, especially noticable when I make a PostScript file. Why?
• My filled contour plot colors look great on the display. But three contours are gray in my PostScript output. Why?
• Why doesn't the NLEVELS keyword to the CONTOUR command give me the correct number of contour levels?
• The colors on my filled contour map projection are completely wrong. What's going on?
• Isn't there a way I can solve all my Contour plot problems?
• Is there a good replacement for the Contour command?
• How can I get rid of this gap in my filled contour plot on a map projection?
• Compare filled contour plots in different graphics systems.
• Can you show me how to display a filled contour plot on a map projection?
• Contouring with CELL_FILL is taking forever! Is there a way to speed it up?
• Can you show me how to use Out-of-Bounds colors with filled contour plots?

Surface Plot Tips

• Is there a good replacement for the Surface command?
• Is there a good replacement for the Shade_Surf command?
• Is there a powerful Surface command replacement that works like the Surface command I'm used to?

General Plotting Tips

• How do I overplot data on a !P.MULTI plot?
• How do I position plots on the display?
• How do I position images on the display?
• How do I turn axis labelling off?
• Why don't graphics windows resize smoothly on my Windows machine?
• How do I leave room for a title when plotting multiple plots?
• How can I create a circle in IDL?
• How do I draw a rubberband box in a regular graphics window?
• How can I print the contents of the current graphics window?
• How can I tell if a graphics window is still open and available.
• Can I force IDL to use exponential axis annotation?
• I finally got my cheapskate boss to update IDL, only to find my favorite RDPIX program doesn't work. Help!
• What is the best way to make a scientific animation in IDL?
• Help! I just want to center my plot on the page with the PRINTER device. Is this possible!?
• I'd like to cut and paste a graphics window from IDL to Powerpoint. Can this be done?
• How do I get nice looking fonts in the Z-Buffer?
• Can I make a JPEG file of a line plot without opening a graphics window?
• What do people use to overplot vectors on their graphics plots?
• How can I create a color (JPEG, TIFF, PNG, BMP) image from an IDL graphics window?
• Have you noticed odd cursor behavior with Mac OS X?
• Can you show me how to display an image with a logarithmic color bar?
• Is there a routine in IDL for clipping polygons?
• How can I display an image with a log-linear aspect ratio in IDL?
• Can you show me how to obtain the location and value of a displayed image?
• What is the best way to produce IDL graphics output for Web or Powerpoint display?
• How can I interactively annotate a plot window in IDL?
• Can you show me how to create a sun symbol in IDL?
• Can you show me how to display a function of two variables as an image?
• Why is the first graphics window in my IDL session always blank?
• How can I create an Angstrom sign?
• How can I create a greater-than-or-equal-to symbol?
• How can I create a less-than-or-equal-to symbol?
• How can I create a degree symbol?
• How can I create a not-equal-to symbol?
• How can I create a prime symbol?
• How do I add a legend to a graphics window?
• How can I create a graphics window with a white background?
• Why does the NASA AL_Legend command display incorrect colors?

Graphics Display Tips (3D)

• How do I create 3D axes?
• How do I add 3D axes to a rendered isosurface?
• How do I display a particle trajectory in 3D space?
• How do I create a 3D scatter plot?
• How can I exaggerate the Z axis of a surface plot?
• How can I grid 3D spherical data to view with SLICER?
• How can I draw a surface plot with axes through the origin?
• How can I shade my surface plot according to its elevation?
• How can I create a semi-transparent surface in IDL?
• Why can't I use the [XY]Range keywords to display just a portion of a surface?
• How can I display my XYZ data as a surface?
• Can you show me how to create a 3D representation of a surface from image ROIs?

Histogram Display Tips

• How can I make a histogram plot that looks like a histogram plot?
• How can I make a histogram plot with logarithmic bins?
• How can I fit a Gaussian to a histogram plot?
• How can I create overlapping, transparent histogram plots?

Image Display Tips

• Is there a device independent, color model independent replacement for the TV and TVSCL commands?
• How can I plot an image profile along any arbitrary line in an image?
• How do I interactively adjust the contrast/brightness of an image using direct graphics?
• How do I interactively adjust the contrast/brightness of an image using object graphics?
• How can I convert an RGB image to a gray-scale image?
• Can you show me how to draw a boundary around a region of interest?
• I'd like to create an ROI mask for my image. How do I do it?
• How do I fit an ellipse to a region of interest?
• "Pixel-interleaved. Band-sequential..." Just tell me this: Where does the 3 go?
• How you show me the IDL Way to turn an 8-bit color image into a 24-bit image?
• How can I add a blend two images together so it appears one image colors the other?
• Is there an easy way to display a maximum intensity projection of an image?
• How can I display a transparent PNG file in direct graphics?
• How can I interactively annotate an image in IDL?
• How can I interactively query an image in IDL?
• How do you set up a map coordinate space so you can draw map boundaries and grids on an image?
• How can I leave room for colorbars when I display multiple images with cgImage?
• How can I brighten up my dark, dull MODIS reflectance images?
• How can I partition image values into distinct colors for display?
• I have a 24-bit image. How do I make a transparent PNG file out of it?
• Does Congrid resize images correctly?

Colorbar Display Tips

• How can I leave room for colorbars when I display multiple images with cgImage?
• How do I display a colorbar with a log-scaled image?
• How do I add a color bar to my graphics plot?
• How can I annotate cgCOLORBAR with my own labels?
• Your nice cgCOLORBAR program won't display my colors. Why not?
• Can you show me how to display an image with a logarithmic color bar?
• When I use your cgCOLORBAR program how come there is a dark line in the color table representation?
• How can I build a discrete color bar with the labels centered on the colors?
• How do I make cgCOLORBAR to use floating point labels?