Magnetic Flux Temporal Curves

Using a time ordered series of files as input, subareas
(various shapes) can be defined and the flux within them
plotted as a function of time (or vs the set of files if
times are not available for the data).

This tool can use several types of image sources selected
via the "source" option menu in the upper RHS. Normally it
will be configured to read all of the images for a given
source. To restrict the range used, enter or modify the
entries in the range area. The "dn" box can be used to
specify a delta; i.e., 2 would use every other image in the
list.

To get started, you should first display an image in the
series using another tool like "movie set" or "file viewer"
(both under File in the main widget). If you are using a
file list, a selector for your list will come up after you
enter the name of the list in this tool and you can just
use it to display an image. You need an image on the screen
to define subareas. Then either use the "pop subarea tool"
button on this widget or from the main widget (under single
window tools) to bring up the subarea tool. Select subareas
and come back to this tool. The subarea list box can be
filled with the ID's (numbers) of the subareas wanted. Or
all subarea or the entire image can be selected.
Alternatively, the "wire selection to subarea tool" option
can be choosen. After selection of this option, any new
subarea defined will be entered in the subarea list for
you.

If times and positions were found in the file headers, you
can use the "track solar rotation" option. This must be set
before the extraction of the temporal curves or you'll have
to re-extract them. The subareas can be defined for
different images in the time series. The image in which they
are defined becomes the reference for that subarea when
rotation tracking is on. A very important caveat is that the
tracking is only done to the nearest pixel. This will
generate some temporal power at a frequency corresponding to
the time it takes a pixel to move its width on the sun from
rotation.

The magnetic calibration uses the pixel size and the scale
factor (gauss per least significan bit). Alas, all pixels
are assumed square with the same size, there is no
correction for solar position. This is reasonable near sun
center. You can also specify a zero level if necessary.
This is also useful if the input is a scaled byte array
though you need to somehow figure out what the zero should
be and the magnetic calibration.

To finally extract the curves, press the gray button labeled
"read files and compute ...". This could take a while,
depending on the number and size of files to read. The
calibrated curves are than internally stored and can be
displayed using the set of buttons and options at the bottom
of the widget. You can plot all the curves or a single
curve. The min and max can be specified, otherwise it is
determined by the range in the curve(s). After a plot, an
over plot can be made. Either the net (signed combination)
or the total flux or both can be plotted. The total flux is
computed by taking the absolute value of each pixel before
summing in each subarea. Various plot windows can be
specified. All the computed curves can be saved in a
specified file. At present this is an fz file and does not
have the times (if any) included. It cannot be re-processed
in a sensible way by the browser but requires an ana or idl
script cognizant of the particulars of the data to use it. A
more sensible, self defining save will be part of an
upcoming upgrade.

The plots can be put on the screen or sent directly to an
eps file. Usually you would select the screen first to see
what you have and then toggle to the eps option and plot
again (the plots are fast). To allow for possible over
plots, the eps file is not immediately closed after a plot
is made. To force a close, hit either the screen or eps
option toggle again. If a new plot (not over plot) is
started, the old one will be closed. The eps file name is
defined when the plot is started, not when it is closed.

To get rid of this window, press help again. To get rid of
the extract cube tool window and this window, press dismiss.
The cube will remain defined.