Make sure you are consistent about how you use x and y . MATLAB prefers y as the row number, because rows are vertical and y is traditionally vertical. MATLAB prefers x as the column number, because columns increase horizontally and x is traditionally horizontal.
If you are expecting that the string G91468166 in handles.input1.string will be interpreted as numeric 1 because you did that assignin() base, then you have not taken into account a couple of things:
- str2double() never pays attention to variables that are set. str2double() pays attention only to the immediate text, and whether the whole of it forms a valid numeric literal. The character vector G91468166 does not form a numeric literal such as 3.8135e-5 so str2double() would say it fails, and convert it to NaN
- the functions that do pay attention to variable names, such as eval(), do not specifically look in the base workspace: they look in the workspace of the current function. The exception is if you use evalin('base')
I suggest you use a different approach. I suggest you use a drop-down list, with the elements arranged in-order. Then instead of looking at the String propertly of a pushbutton, you look at the Value property of the drop-down list, and that will give you the index immediately (just make sure you check whether the Value is [] for the case where nothing has been selected yet.)
