topic Re: How to create isopleths of dissolved oxygen for lake? in Discussions

How to create isopleths of dissolved oxygen for lake?

ayman — Tue, 18 Sep 2018 18:33:40 GMT

I am trying to create an isopleth of dissolve oxygen for a lake as shown below using JMP. The data I have includes month, depth, and dissolved oxygen.

Re: How to create isopleths of dissolved oxygen for lake?

gzmorgan0 — Tue, 18 Sep 2018 20:01:02 GMT

In JMP there are two methods that might work, depending upon your table setup. Likely a contour is what you want

Below is a picture, from JMP sample data Little Pond. Its x axis is spatial distance not time. You will have to customize the color scheme. A script to create the picture follows.

You can produce a contour with Main Menu Graphs > Contour Plot or Graph Builder. Contour plot has more customization.

From Contour choose Days and Depth for X and Dissolved Oxygen for Y Ask to fill areas. You can choose your levels for the Z variable (Dissolved Oxygen).

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Little Pond.jmp" );

obj = dt << Contour Plot(
	X( :X, :Y ),
	Y( :Z ),
	Show Data Points( 0 ),
	Fill Areas( 1 ),
	Label Contours( 1 ),
	Transform( "None" ),
	Specify Contours( Min( -4 ), Max( 8 ), N( 7 ) ),
	SendToReport(
		Dispatch( {}, "Contour Plot Graph", FrameBox, {Frame Size( 594, 326 )} )
	)
);

Re: How to create isopleths of dissolved oxygen for lake?

ayman — Tue, 18 Sep 2018 22:00:59 GMT

It is working! thank you so much.

Re: How to create isopleths of dissolved oxygen for lake?

gzmorgan0 — Tue, 18 Sep 2018 22:26:07 GMT

Oh, one item that is on a wish list that I hope JMP tackles in the next version is to separate the outline of shapes and the fill.

Since I liked your plot with the contour lines visible and a different color than the fill, I decided to see what it would take to get the outlines. It's not too bad. Here is the picture. The script is attached; it was tested in JMP12, 13, and 14.

Re: How to create isopleths of dissolved oxygen for lake?

ayman — Wed, 19 Sep 2018 16:32:04 GMT

Thanks!

How can I make the line smoother?

Re: How to create isopleths of dissolved oxygen for lake?

XanGregg — Wed, 19 Sep 2018 16:52:10 GMT

For smoothing, the most general option is to create a smoothed version of your data in a new column with a regular modeling platform or the Guassian Process platform. And then graph that data.

In JMP 14, there is a smoothness slider in Graph Builder's contour element which will dynamically apply a kernel density smoother. However, it doesn't have the line labeling options of the Contour Plot platform.

Re: How to create isopleths of dissolved oxygen for lake?

ayman — Wed, 19 Sep 2018 17:05:22 GMT

Thanks!