On a graph you can manually enter whatever text you wish to; however, I want DIAdem to be able to do this automatically for the slope and intercept of whatever channels I choose to display. (i.e. like can be done for Axis-Text)
First create new channels that have the data that you want displayed, in this case slope and intercept. Then create a table to be displayed on the graph so that it has two columns then choose column 1 to be 'expression' and pick the channel that you want to display. Choose column 2 to be 'channel' and again pick out the data that you want displayed. In this way you can use this in an autosequence so that the table will display the new slope and intercept for each new set of data.
Are you trying to get the equation of a particular curve or just the slope between two point?
The easiest way to enter custom text in a graph is to embedd a text variable (like T1) in the graph. This variable will be blank and only when needed can be filled with the value of a slope. You can use one of the buttons on graph to run autosequences and have a script that will calculate and display the slope.