@dharr I copied our code into mine. Didn't realize 'Plot0' was needed too. Thanks. 

@dharr 

It does't work for me. I didn't even know about 'start', etc. at the bottom start,end buttons and distance look like input and do not show any numbers when I click on two points 

Indeed I can enter numbers in the boxes. When I click reset the numbers I entered disappear and nothing else happens.

When I try it in my code it doesn't work ... it does not recognize 'Plot0'

Download DealeyPlazaToo.mw

@Traruh Synred 

The real problem is not that I don't know how to extract numbers from a line using op, but that I don't know how to access the line I've drawn with Sketch from the command line. I could have explained that better.... nor does Sketch seem to provide any way to make measurements via its interface. . 

@dharr Thnks, but...That only tells me the number of pixels in the picture. What I'm trying to do is 'measure' the length of a line I've drawn on the picture using Sketch. I sent in my 'self' reply a version of the picture that has the line. 

I've found an online tool that does this, but as I'm working in Maple it would be convenient to do it in Maple and be able to enter the numbers into my procedures. 

@Traruh Synred That worked. The linked version shows the arrows whose length I wish to obtain.

I will try uplloading a link as the version copied into the question did show the only thing I did which is draw some arrows/lines with Skietcher. Maybe link will preserve that better.

My question is how I find the length of such lines...DealeyPlazaToo.mwDealeyPlazaToo.mw

@acer I only have 2018.

I guess I could ask my former employer if they be willing to let me have the upgrade. I am actually working on a little 'home' project relevant to them. 

@Carl Love Indeed I'm using 2018. It's all I have access to. It appears to have no 1D mode (I didn't even know there was a choice).

@Carl Love Perfect!

The problem seems to be missing '#iinclude <iostream>".. 'string' is already defined in ROOT so it's clear why .'L Test.cpp'. However, its clear why 'g++ Test.cpp' doesn't complain.

As someone much inclined to typos, it's going to be hard for me to code w/o better feedback from the compiler.

@Thomas Richard Thanks!!!!!!!!!!

I was slow on the uptake there. I kept thinking I needed a 'write' or 'Export' function, rather than that it was an option fo 'C' command.

@Thomas Richard Thanks. I know to supply a string for the file name. What I don't know is how to supply output of the 'C' . It is not a string nor is it indexable. I would have though outputting it as a text would be the point of converting it to C.

@acer Just what I need.

@Christopher2222 Thanks.

@dharr What I want to do is somehow combine data from different Maple runs. I have some kind of memory leak problem that only allows me to simulate only about 200 events. If I could add the 'Histograms' from these runs I could get adequate stats. Not ideal, but it does sound like maybe '.m' files might be a way to do that.