Working with axis pins in VCDAT

There is a new feature in the VCDAT that we want to turn your attention to. Next to the axis there are now little icons of the pin. It can be used to pin/unpin the axis. If you need to work with the slice  in time and pressure for example, you can zoom in on the slice and then pin this dimension. This way any variable you will subsequently work with, will automatically have this dimension zoomed. 

Often one needs to look at the zoom of a particular dimension, say only a window in time, or particular region in (lon, lat) space or particular height region. You will now have the ability to choose say a height region, lock the height dimension, and now whenever you plot any variable that has this dimension, it will be displayed within chosen height region only, so effectively the default height region is now the chosen min and max values.  If you are curious to see the full height but do not want to reset the new default, you can move the sliders without unlocking the height dim.  If on the other hand you want to reset the defaults, just unlock the lock and choose new region, then lock the dim again to keep it as new default.  You will find it extremely handy at times. The locks work also on the dimensions/axis order and are very handy when you need to change the pressure levels to be displayed from highest to lowest.

Here are the possible states of the pin:
pinned, unpinned and undone (state changed due to incompatible range of  selected variable)

Exercise

1) Let's open a file from the sample-data directory called era40_tas_sample.nc and choose a variable called 'tas'. The data spans 1991-1-1 to  1993-12-1. We will choose a slice in time using the pull down menu next to the time button name and select 1992-1-1 to 1992-12-1 ant then seal it with a pin, by clicking on the pin.

2) Let's now open another file from the sample-data directory called era40_sst_sample.nc. Since the chosen slice in time is within the time range of this dataset, your selected time slice will remain selected.  

3) Now open a file with a very different time range, for example file 'clt.nc' from the sample-data directory. Since the chosen slice in time is outside the time range of this dataset, the time sliders will show the default whole range selection and the pin will show a status in between 'pinned' ad 'unpinned'

4) You can now select new time range and pin the pin gain to hold this new setting as a new time range default.

5) Once the pin is in the 'pinned' position, you can move the sliders, and this will change the default range to whenever you moved you sliders too. 

6) If you 'unpin' the pin and then move the sliders, you default goes back to the standard default setting - the whole dimension range. So if you then open another file, its time range will then be a default full range.

Editing plots with the new VCS canvas GUI

We are very excited to introduce the brand new feature in VCDAT - namely the canvas GUI that lets you edit the plot, move the text with drag and drop capability and change the text with a double click. The new feature is introduced in the CDAT 5.0 release.

You can work either with the standard canvas, or the new canvas GUI. You cannot have both at the same time, so you need to first select the option to have you canvas appear as the GUI canvas.

Start VCDAT, and check that the VCS Canvas GUI is selected

% vcdat  

The little confirmation window will appear to warn you that if you already have a VCS canvas open, you will lose the work in this canvas, it will be deleted and the new requested canvas will be a GUI canvas.

The VCS canvas GUI looks like this:

We will be working with the 'Edit Plot' tab

From a pull down menu in 'Source' you can choose to edit the title or axis labels text or add other text items. Click on the little arrow on the right to see the pull down menu

For example select 'Title' and enter the 'This Is a Title' text, then press enter. The title of the plot will be changed. Now you can click on this text on the plot and the red arrows will surround the text, experiment with the resizing and positioning of the text.

Manipulate with the title until you are happy with the placement and the size:

In the same way experiment with changing the placement of the color table label, you can drag it to show up vertically on the right side for example. You can also resize the whole template, or move it around.

If you position your cursor in the lower part in the green editable area for example, the popup will show up with the help on what you can edit and how:

Also click on the 'Additional Controls' to see forms with the detailed options for the text, axis and labels. 

And lastly. don't forget to save the template by clicking on 'Save Template' button, so you can reuse the positoning of elements with other variables or datasets.

We hope you will find this new exciting feature extremely useful.