Rank: 792 based on 90 downloads (last 30 days) and 9 files submitted
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Andrew Stevens

E-mail
Company/University
US Geological Survey
Lat/Long
37.4556999206543, -122.1700973510742

Personal Profile:
Professional Interests:
oceanography, sediment transport, benthic habitat mapping

 

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Files Posted by Andrew View all
  • 1 - 5 of
  • 9
Updated   File Tags Downloads
(last 30 days) 		Comments Rating
21 Jan 2010 SP_PROJ Convert to and from US state plane coordinates Author: Andrew Stevens coordinate transforma..., earth science, gis 5 1
  • 5.0
5.0 | 1 rating
18 Aug 2009 Screenshot CURVVEC draw curved vectors from 2D vector data Author: Andrew Stevens quiver, stream lines, vector field, 2d, specialized plotting 10 1
  • 5.0
5.0 | 1 rating
01 Apr 2009 Screenshot BIN2MAT Create a matrix from scattered data without interpolation Author: Andrew Stevens reshape, vector, gridding, accumarray 3 0
  • 4.0
4.0 | 1 rating
31 Mar 2009 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens data import, data export, esri, arc, raster, grid 23 7
  • 4.5
4.5 | 2 ratings
04 Mar 2009 Screenshot GESCATTER Create a scatter plot in Google Earth (.kml) Author: Andrew Stevens kml, data export, google earth, scatter 22 3
  • 4.66667
4.7 | 3 ratings
Comments and Ratings by Andrew View all
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  • 5
Updated File Comments Rating
31 Mar 2011 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens

Edgar,

The default precision for the function is %0.3f, so you should get 0.075 as the cell spacing. I tried the following code to verify:

%generate synthetic data with desired %cell spacing
xi=0:0.075:1;
yi=0:0.075:1;
[xm,ym]=meshgrid(xi,yi);
zm=peaks(numel(xi));

%call arcgridwrite
arcgridwrite('test.asc',xm,ym,zm);

%look at output
type('test.asc')

The results look correct to me. Let me know (by email) if you have further questions.
09 Mar 2010 Matlab script to read and plot NCEP/NCAR 4x Daily Reanalysis data Matlab script to read and plot NCEP/NCAR 4x Daily Reanalysis data Author: Paula Moreira

Why not use OPeNDAP which has a tool to read NCEP Re-Analysis data (as well as many other datasets) directly into matlab?

http://opendap.org/download/ml-structs.html
27 Jan 2010 ascii2xyz convert ARC ASCII text file to xyz Author: Andrew Stevens

Fran,

This file is intended to read in an ASCII file produced by ARC GIS containing raster data. A properly formatted ARC ASCII file has header information which your file does not apparently have. Type 'help ascii2xyz' to see the required header format.

Andrew

10 Sep 2009 xyzplotter Transforms lists xin,yin,zin into matrices which can be used with the functions surf and mesh. Author: Jack Kohoutek

This code worked fine for the example that I tried. Here are a couple comments and questions that I think, if addressed, will improve the code and clarify its function.

1)The help section is in a non-standard format and an H1 line would be useful.
2) What does the code do with repeat x and y values?
3) What is the cell-size of the resulting grid? Answers to 2 and 3 should be added to the help section.
4) Efficiency: This code uses a triple loop to fill the grid. For large datasets, this will be extremely slow. An alternative approach is to use a combination of HISTC and ACCUMARRAY to populate the grid that will be fast.

-Andrew
31 Mar 2009 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens

Colin,

Thanks for your comments. I found after playing with a couple examples, I determined that if I simply change the output filename from .txt to .asc that the file can be read directly into arc without doing the raster conversion.

I would also be careful with your modification of the way the header is written in the output file. Your modification forces the cell-size to be an integer which would produce a large error in many of my datasets.

Andrew
Comments and Ratings on Andrew's Files View all
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  • 26
Updated File Comment by Comments Rating
26 Jan 2012 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens Westergaard, A

The above mentioned matrix has 350 rows and 300 columns. Values are double.
25 Jan 2012 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens Westergaard, A

Andrew,
Thank you for sharing your work. As I am new to MatLab, I hope you or others have time for some guidance: In Matlab I have a matrix with values [-1:1]. I want to export this matrix to ArcMap. What would the syntax be for this? Thank you in advance.
17 Jan 2012 GESCATTER Create a scatter plot in Google Earth (.kml) Author: Andrew Stevens Roshan, John

Works great!

The default placemark symbol and color could have been set to something more visible though.
08 Oct 2011 GESCATTER Create a scatter plot in Google Earth (.kml) Author: Andrew Stevens Chandrakumar

the foo.kml is which file?
26 Jul 2011 ascii2xyz convert ARC ASCII text file to xyz Author: Andrew Stevens Ric

Hey,
i'm trying to use this script, but it just outputs values of 0.051 instead of 51.(and about 10-17 numbers (depending on the coordinates) following) - it also would be just great to have an option of getting the script to output a .txt file, containing longitute, latitude, altitude (seperated by anything) - as my coal is to get ascii-data into a sql database. do you have any ideas?
as i'm not experienced in matlab in any way so it's not possible to improve the script myself though it's doing exactly what i need (exept for the output-prescision and output-file).
thank you very very much for writing the script in the first place, and even more for helping me!

best regards, ricardo
Top Tags Applied by Andrew
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  • 45
data export, data import, gui tools, raster, vector
Files Tagged by Andrew View all
  • 1 - 5 of
  • 9
Updated   File Tags Downloads
(last 30 days) 		Comments Rating
21 Jan 2010 SP_PROJ Convert to and from US state plane coordinates Author: Andrew Stevens coordinate transforma..., earth science, gis 5 1
  • 5.0
5.0 | 1 rating
18 Aug 2009 Screenshot CURVVEC draw curved vectors from 2D vector data Author: Andrew Stevens quiver, stream lines, vector field, 2d, specialized plotting 10 1
  • 5.0
5.0 | 1 rating
01 Apr 2009 Screenshot BIN2MAT Create a matrix from scattered data without interpolation Author: Andrew Stevens reshape, vector, gridding, accumarray 3 0
  • 4.0
4.0 | 1 rating
31 Mar 2009 ARCGRIDWRITE Write gridded data set in Arc ASCII Grid Format Author: Andrew Stevens data import, data export, esri, arc, raster, grid 23 7
  • 4.5
4.5 | 2 ratings
04 Mar 2009 Screenshot GESCATTER Create a scatter plot in Google Earth (.kml) Author: Andrew Stevens kml, data export, google earth, scatter 22 3
  • 4.66667
4.7 | 3 ratings

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