Best way to graph a discontinuous data set? | IgorExchange

Best way to graph a discontinuous data set?

gseaborn	August 29, 2008 - 10:49		Permalink
Posts: 16 Joined: 2008-08-01 Location: Canada	I have a numeric data set that is interspersed with "-1" values. Wherever there is a "-1", I would like the graph not to plot the point, and to make a gap between the two adjacent points (not join them up). Is there any easy way to do this? I know I can use DeletePoints to remove the points that have a value of "-1", but I'm not sure how I can make it so that the line graph is plotted discontinuously. Thanks Login or register to reply

aclight	August 29, 2008 - 12:08		Permalink
Posts: 563 Joined: 2007-03-01 Location: United States	Igor plots a gap where the value of a wave is NaN (not a number), so you just need to replace all -1 values in your wave with NaN and then display the wave. Something like: foo = foo[p] == -1 ? NaN : foo[p] should work for the replacement. Login or register to reply

gseaborn	August 29, 2008 - 12:33		Permalink
Posts: 16 Joined: 2008-08-01 Location: Canada	Thanks - that's perfect. Login or register to reply

patarroyo	September 23, 2008 - 12:59		Permalink
Posts: 51 Joined: 2008-07-08 Location: United States	aclight, where can I learn more about the syntax that you used? That functionality looks interesting, but I don't follow it. Login or register to reply

andyfaff	September 23, 2008 - 14:07		Permalink
Posts: 476 Joined: 2007-09-11 Location: Australia	It's in the IGOR help browser. Look for ?: in the index. On the LHS you have a "True or false" question. Part 1: foo[p]==-1? which points in foo are equal to -1? Part 2: foo= ....... NaN : foo[p] where the question in part 1 equates to True, set the value of foo to NaN. Where the question equates to False, leave the point as it is. aclight wrote: Igor plots a gap where the value of a wave is NaN (not a number), so you just need to replace all -1 values in your wave with NaN and then display the wave. Something like: foo = foo[p] == -1 ? NaN : foo[p] should work for the replacement. Login or register to reply

vinodmagic	April 20, 2012 - 21:30		Permalink
Posts: 6 Joined: 2012-04-20 Location: India	What should i do if i want to replace all values within a wave between two given points (say between point 2 and point 100) by NaN? Login or register to reply

bech	April 20, 2012 - 21:34		Permalink
Posts: 54 Joined: 2007-10-20 Location: Canada	vinodmagic wrote: What should i do if i want to replace all values within a wave between two given points (say between point 2 and point 100) by NaN? Just write w[2,100]=NaN Login or register to reply

jtigor	April 21, 2012 - 07:28		Permalink
Posts: 180 Joined: 2007-09-04 Location: United States	bech wrote: Just write w[2,100]=NaN Just to be painfully clear, note that will be inclusive of points 2 and 100. If you want points between 2 and 100, exclusive of the endpoints, you want to use w[3,99] = NAN Apologies if this is too close to stating the obvious. Login or register to reply

vinodmagic	April 22, 2012 - 10:08		Permalink
Posts: 6 Joined: 2012-04-20 Location: India	Thanks, it worked. Was really so easy!! Login or register to reply