Thread Subject: change data format in plot window?

Hi,

I could imagine that other people had this problem, but I
did not find anything similar by using the newsgroup search:

Is there a way to change the format the data is displayed in
the plot window? If I plot vectors with more than 10^5
elements and want to find out an exact index position by
zooming into the plot, the numeric format is limited to 4
digits after the decimal point (like the 'short e'-format in
the command window), and it is not directly possible to
determine the exact index of a data point.
This is especially annoying when you display vectors with
even more elements. E.g. a displayed index of "1.2345 x
10^8" could be any index between 123450000 and 123459999.

If it is not possible to change the data format of the axes,
is it optionally possible to change the data format of the
data cursor? I know, that it is possible to export the value
of the data cursor to a workspace-variable and display it
there in your favorite format, but if you want to check many
data points quickly, this becomes very laborious.

Any suggestions?

Holger

"Holger Kirchhoff" <holkir@cs.tu-berlin.de> wrote in
message <fvuf1f$4g5$1@fred.mathworks.com>...
> Hi,
>
> I could imagine that other people had this problem, but I
> did not find anything similar by using the newsgroup
search:
>
> Is there a way to change the format the data is displayed
in
> the plot window? If I plot vectors with more than 10^5
> elements and want to find out an exact index position by
> zooming into the plot, the numeric format is limited to 4
> digits after the decimal point (like the 'short e'-format
in
> the command window), and it is not directly possible to
> determine the exact index of a data point.
> This is especially annoying when you display vectors with
> even more elements. E.g. a displayed index of "1.2345 x
> 10^8" could be any index between 123450000 and 123459999.
>
> If it is not possible to change the data format of the
axes,
> is it optionally possible to change the data format of the
> data cursor? I know, that it is possible to export the
value
> of the data cursor to a workspace-variable and display it
> there in your favorite format, but if you want to check
many
> data points quickly, this becomes very laborious.
>
> Any suggestions?
>
> Holger


After plotting your data, try this convoluted command which
will print 15 decimal places in the data cursor:

set(datacursormode,'UpdateFcn',@(Y,X){sprintf('X: %
0.15f',X.Position(1)),sprintf('Y: %0.15f',X.Position(2))})

"Holger Kirchhoff" <holkir@cs.tu-berlin.de> wrote in message
news:fvuf1f$4g5$1@fred.mathworks.com...
> Hi,
>
> I could imagine that other people had this problem, but I
> did not find anything similar by using the newsgroup search:
>
> Is there a way to change the format the data is displayed in
> the plot window? If I plot vectors with more than 10^5
> elements and want to find out an exact index position by
> zooming into the plot, the numeric format is limited to 4
> digits after the decimal point (like the 'short e'-format in
> the command window), and it is not directly possible to
> determine the exact index of a data point.
> This is especially annoying when you display vectors with
> even more elements. E.g. a displayed index of "1.2345 x
> 10^8" could be any index between 123450000 and 123459999.

Use the zoom mode object's ActionPostCallback function to adjust the
XTickLabel property of the axes after zooming.

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/zoom.html


x = 1e5:1e4:3e5;
y = (x/1e4)*5;
plot(x, y);
zoom('on');
zM = zoom(gcf);
set(zM, 'ActionPostCallback', ...
    @(figh, eventobj) set(eventobj.Axes, 'XTickLabel', ...
    sprintf('%5.3f|', get(eventobj.Axes, 'XTick'))));


> If it is not possible to change the data format of the axes,
> is it optionally possible to change the data format of the
> data cursor? I know, that it is possible to export the value
> of the data cursor to a workspace-variable and display it
> there in your favorite format, but if you want to check many
> data points quickly, this becomes very laborious.

See the last example on the documentation page for DATACURSORMODE:

http://www.mathworks.com/access/helpdesk/help/techdoc/ref/datacursormode.html

--
Steve Lord
slord@mathworks.com