Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
I used IDL 4.01 extensively on a Sparcstation in 256 color mode and have become comfortable with the interface. Recently, I have begun using IDL on a Windows NT 3.51 machine and have encountered problems with dynamic color modification using xpalette and loadct. In 16 bit color mode (64K colors available), once an image is tvscl 'd, the color map is frozen until it is redisplayed. If I start xpalette and select a different map, the original map is displayed in the color bar icon until I stop and relaunch xpalette. The sliders don't change the image color map dynamically either. a=sin(indgen(100,100)*1.0) ; make an array to scale loadct,0 ; select the default bw palette tvscl,a ; a bw image appears loadct,1 ; select the blue-white palette (image is still bw here) tvscl,a ; bw image replaced with blue-white image I have spoken with RSI technical support and remain unhappy. There answer essentially is that IDL only handles colors appropriately under 256 color mode and suggest going into the control panel and changing color mode from TrueColor or 16bit. This involves restarting Win NT! Aaaagh! I have an application that takes data and needs a 16 bit color space for display but would like to use IDL for further analysis. This may be fixed in a later release of IDL. But the suggested sequence is run application 1, save data, reboot, run idl and look at data, exit, reboot, and repeat. Has anyone come up with a workaround? I can't be the only person to have hit this. I don't know if this could be done by rewriting xpalette (written in IDL). By the way, IDL on a 133 MHz Pentium with 64M Ram runs about twice as fast as on a Sparc 20. Not a scientific benchmark. regards, Peter Lorraine GE Corporate Research & Development lorraine@crd.ge.com