Category plots: a serious limitation in Igor Pro?

Hello,

I am facing serious limitation in Igor pro. I have data points on the y-axis going from -15 to 5. The category plot can only be plotted growing up from zero and hence my column is inversed. I tried every single way to try to plot a column growing upwards from -15 to 5 but failed.
Any suggestion?

Kind regards,
Katy
Here is an example. Note that the idea that the column grows from (e.g. -15 to ~-7). You could argue that we could reverse the y-axis but that will leads to illogical order of the y-axis. So I wished to have the circled black symbol sitting at the top of the column not at its bottom?

I think the problem is to do with that the base line of category plots is always set to positive number or zero but negative values are not possible! A real challenge!


Thanks
Katy
Would this do what you want?

categories      data        minus15
    a       -6.5        -15
    b       -8      -15
    c       -9      -15
    d       -11     -15
    e       -7.5        -15
    f       -7      -15

Window categoryFromMinus15() : Graph
    PauseUpdate; Silent 1       // building window...
    Display /W=(39,273.5,433.5,487.25) data,minus15 vs categories
    ModifyGraph mode(minus15)=2
    ModifyGraph toMode(data)=1,toMode(minus15)=2
    SetAxis left -15,0
EndMacro

--Jim Prouty
Software Engineer, WaveMetrics, Inc.
Here's another way to do it. Like Jim's this requires some trickery:
Make/O/T categories2 = {"a","b","c","d","e","f"}
Make/O data2 ={-6.5+15, -8+15, -9+15, -11+15, -7.5+15, -7+15}   // Original data plus 15
Display data2 vs categories2
ModifyGraph offset={0,-15}
SetAxis left, -15, 0