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Misange Misange is offline
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Default how to locate a point on excel graph?

Hi
here
http://www.excelabo.net/exemples/sgfc-coordonneesgraph
you can dowload a file which answers your demand.

I am afraid it is in french ! if you do not understand french here is
the translation of the key instructions:


paste in the frame (actually this is an empty graph) a picture of a
graph you want to analyze (i.e. one scanned from a document). Resize the
picture so that it is just slightly larger than the frame.
Do not zoom

Click on the mouse move button
pass the mouse over the graph. The coordinates are displayed in the blue
zone ("points sous la souris")

Now define the coordinates of the axis origins:
- click on mouse move, place the mouse on the (0, 0) point on the graph.
report the values displayed in the blue zone in the green one (below
"origine des axes"). If the x (or y) axis does not start at 0, write the
actual value under X0 and Y0
Now collect the values for the maximal value of each axis: place the
mouse over the maximal value of the axis, note the coordinate in the
blue zone, report it under "maximas des axes" and indicate the
corresponding real values under xmax and ymax .

Now, to collect values displayed in the graph
Click on mousemove
click on each point of the graph you want to collect
the coordinates of the point are displayed in the purple zone,
"translated" using the coordinates of the axis.
If you are using a logaritmic scale for the axes you will have to adapt
the formulas used to calculate the values.

each collected value should be automatically copied under the yellow
zone but there is a problem with this function if I remember well in
2007 and I had no time to look at this more carefully.

The class module was written by Serge Garneau.
I use this tool quite often, for instance to redraw some graph with a
cleaner presentation.


Misange


Luke M a écrit :
Jon,
Not intending to thread-jack, but are both of those possible? I was recently
asked by a colleage if it was possible to randomly pick a point on a chart
and have excel then spit out the coordinates.

Expanding on this, would it be possible to do something similar using a
scanned image (say, a graph from a textbook)?