My lab is trying out Origin vs Sigmaplot. I'm stuck on a bit of
configuration that *should* be relatively easy (I think)
I have a series of plots (simple sigmoidals). The X-axis is composed of pCa
values and the Y axis
is specific activity.

The pCa values are *not* periodic, eg they range from 5 to 8 in varying
increments.
What I *need* is for Origin to basically ignore the scale on the X-axis, place
a tick at each data point and make these marks at regular intervals. Yes, then

a pCa difference of 0.3 will cover the same distance as a difference of 0.5,
but
for our purposes that is OK.

Right now, as you can imagine, Origin plots some of the points very close
together
and others far apart...it looks quite odd.

I'm very impressed with Origin and plan on casting my lab vote in favor of it
over
SigmaPlot, but I have to be able to get the above configuration.

Any and all help would be appreciated!

Thanks,

To plot your unevenly X spaced data with equal spacing is actually quite
easy. For example, if you have 2 columns of data (X and Y), with the X
values unequally spaced, double click on the X column heading. This will
open the Worksheet Column Format Dialog Box. Now, in the Set Column As
dropdown list, select None. This will now disregard the X column and plot
the data against the row number (evenly spaced).

If you also want the original X data to appear as tick marks, double click
on the X axis tick labels. This will open the Bottom X Axis Tick Labels
dialog box. In the Tick Label Type dropdown list, select Text From Dataset.
Then, specify the X dataset name ( e.g. data1_a )in the dataset input line.
Depending on the number of datapoints you have plotted, you may need to make
some adjustments to the number of axis ticks.