| Re: beginners plotting question [message #14384] |
Wed, 24 February 1999 00:00 |
fireman
Messages: 49
Registered: August 1991
|
Member |
|
|
Nan Galbraith (ngalbraith@whoi.edu) wrote:
: I'm plotting a data return timeline. I'm forcing the value of good data
: to 0 and missing data to 9999, then plotting with a range of +/- 1. I'd
: like to mark the start and end of the lines with a symbol of
: some kind, like this:
: bin 1 |--------------| |--------------------|
: bin 2 |------------------------|
: bin 3 |---------------------------------|
: Is there a first-difference function? I could use that if I could find it,
Yes - use SHIFT.
Try something like this:
IDL> dataflag=[0,0,0,0,1,1,1,0,0,0,0,0,0] * 9999
IDL> diff=dataflag-shift(dataflag,1)
IDL> N=n_elements(dataflag)
IDL> ends=where(diff ne 0,intervals)
IDL> ends=[0,ends,N-1] ; assumes you have data at start,stop
IDL> t=indgen(N)
IDL> plot,t,dataflag,yrange=[-1,1],/nodata
IDL> for i=1,n_elements(ends)-1,2 do $
oplot,t[ends[i-1]:ends[i]],dataflag[ends[i-1]:ends[i]]*0, linestyle=-1
--
-- Gwyn F. Fireman
-- General Sciences Corporation / MODIS Characterization Support Team
-- Gwyn.Fireman@gsfc.nasa.gov 301-352-2118
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
