For the rest of this tutorial:

$1.)$ Using the scatter$()$ function $($you could use any plotting function$)$ make a mark on

the point that the user enters in the x$1$ and y$1$ fields. The user enters the following $($x$1,$

y$1)$ values and after each pair $($x$1,$ y$1)$ press the $$mark the image$$ button. All the points $($Ex:

$(200,200),(400,400),(700,700),(900,900))$ that the user enters have to marked separately

and held on map until the program is exited. The value of an x$1$ EditField can be read using

app.x$1$EditField.Value. Similarly, the value entered in the y$1$ field can be accessed.

$2.)$ Create the startupFcn$()$ call back from the code Browser section and set initial value

of $100$ for the Editfields x$1$ and y$1.$ Note that the input to these fields could be string

and you can use the num$2$str$/$str$2$num function if necessary.

$($Make sure to check command window for errors if any$)$