# Chad Greene

### NASA Jet Propulsion Laboratory

I am interested in the floating ice shelves that fringe East Antarctica. My current work is toward building a better understanding of how climatology influences glaciology via oceanography. I also have some experience with the acoustics of gas hydrates and oceanic methane bubbles.

Homepage: www.chadagreene.com

Professional Interests: Antarctic ice shelf dynamics, sea level rise, underwater acoustics, methane hydrates

Note: I will not do your homework for you and I will not respond to emails directing me to a question posed on the Answers forum.

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**Content Feed**

Can anyone help me with the a tentative guide on how to average across the two dimensions of a 3d array, and loop it across 86 timesteps?

If you have a temperature data cube T whose dimensions correspond to lat x lon x time, the simplest way to get an 86x1 array of ...

11 Tage ago | 1

| accepted

Better “centerpoint” than centroid of a concave polygon

I added a polycenter function to do exactly what you need in the Climate Data Toolbox for Matlab. If you have a shapefile, the...

14 Tage ago | 0

What should go in a next-generation MATLAB X?

If I could design Matlab from scratch I'd get rid of semicolons to suppress output, and make element-wise operations the def...

15 Tage ago | 0

What should go in a next-generation MATLAB X?

I'd like to define ranges using square brackets for inclusive and rounded brackets for exclusive. So insead of if x>=20 & x<30...

16 Tage ago | 0

How can I convert a shapefile boundaries to lat and lon?

If it's a standard map projection, use projinv.

17 Tage ago | 0

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How to find a figure's centroid inside a polyshape?

Also answered here, but reposting my answer in case anyone stumbles upon this thread. I just ran into this problem when trying...

17 Tage ago | 0

Better “centerpoint” than centroid of a concave polygon

I just ran into this problem when trying to place a text label in the middle of a crescent-shaped ice shelf. The centroid or the...

17 Tage ago | 0

Stereographic plot of Sea Surface Temperature Data around Antarctica.

Hi Ravi, There are a couple of ways to do this. Here's one way: Turn your vectors of latitude,longitude coordinates into 2D ...

etwa ein Monat ago | 0

Submitted

gridbin

A MATLAB function for gridding large datasets of scattered data.

etwa 2 Monate ago | 12 downloads |

Submitted

maskoverlay

A MATLAB function to easily overlay a mask.

etwa 2 Monate ago | 10 downloads |

Submitted

fast-ice

Matlab functions for loading Alex Fraser's fast ice dataset.

2 Monate ago | 3 downloads |

plot using latitude and longitude

That looks like you have scattered data. If you have an array of latitudes, an array of longitudes, and a corresponding array of...

5 Monate ago | 0

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polybuffer distance in meters?

I think you've got it right, Alex, but this calls for an explanation of the phrase numeric scalar. The word numeric just means a...

5 Monate ago | 1

| accepted

ploting 2d graph of a vector

You've pretty much got it, but you'll need to define a range of t values, and a value for the constants A, and B. You also need ...

5 Monate ago | 0

| accepted

Submitted

Climate Data Toolbox for MATLAB

A set of low-level functions and tutorials for analyzing and displaying Earth science data.

5 Monate ago | 231 downloads |

Specific color corresponding to specific data using contourf colormap

Perhaps @Kelly Kearney's contourfcmap is what you need?

5 Monate ago | 0

Make a vector plot of the velocity field in polar coordinates

Can you use cart2pol to convert the coordinates and vector components to polar coordinates?

6 Monate ago | 0

Why ?? Undefined function 'crosscorr' for input arguments of type 'double'.

crosscorr is part of the econ toolbox. If you don't have that toolbox, you can probably rewrite your code to use xcorr instead. ...

6 Monate ago | 0

Fit data recorded with different internal clocks

This is an interesting problem. If you can identify a few peaks that occur throughout the 600 s measurement, and those peaks are...

6 Monate ago | 0

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How to create map with [x;y] coordinates? Mapping toolbox

No guaratees on the accuracy of the attached functions, but you may be able to convert between lat,lon and x,y using the attache...

6 Monate ago | 0

| accepted

How can i solve for this issue with the logical flow

I think the error is here: term3=q(i-1)*((r(i)-dr)/r(i)*dr); The first time through the loop, i=1, meaning i-1=0. There is no...

6 Monate ago | 0

| accepted

Adding line change the size of the image

Can you get the axis limits before plotting the lines, and then set the axis back to those limits afterwards? Something like thi...

6 Monate ago | 0

Color along line in polaraxes

What if you interpolate along a dense line and plot with polarscatter? I'm thinking something like this: theta = linspace(0,...

6 Monate ago | 0

| accepted

How to make a surface plot of imported data of a numerical function z=f(x,y)

Just to be clear, you already have the data, and it takes this form M = [x y z]; where x, y, and z are columns? My next qu...

6 Monate ago | 0

time position in graphic

This question is pretty vague, but here's pi displayed at the bottom right corner of a plot: txt = text(1,0,num2str(pi,'%4i'),...

6 Monate ago | 1

| accepted

I have a climatic dataset of a region where I am calculating time series (for drought index). The dimension of the dataset is 164*153*1416 (1416 months in the dataset and the others are the location). How I can average this over space and time?

To get a map of average SPEI, SPEI_mean = mean(SPEI,3,'omitnan'); and that calculates the mean along the third dimension (ti...

6 Monate ago | 0

| accepted

Antarctic Mapping Tool: how can I evaluate the distance of a point from the coastline?

The easiest solution is the dist2mask function in the Antarctic boundaries add-on for AMT. Syntax is d = dist2mask('openocean'...

6 Monate ago | 0

How to mask a 3-D raster using a multiple feature attribute shapefile?

Try this: mask = inpolygon(X,Y,[roi.X],[roi.Y]); You don't even need to remove the trailing nans. :)

6 Monate ago | 0

how to turn netcdf into contour map

Hi Abigail, The first thing I do with a netcdf file is type ncdisp('myfile.nc') to see what's inside it. If you have some ...

6 Monate ago | 0

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Extracting data from matrix

To only plot the ocean data, try masking out the land data by setting those values in A to NaN. like this: A(B==1) = NaN; % se...

6 Monate ago | 0

| accepted