Teaching Geoscience with MATLAB^®

Workshop: Carleton College- Northfield, MN

This post was edited by Sarah Nakamoto on Jan, 2021
Hi All:

When Frederik shared his revelation on publish, he opened my eyes to webread.m to bring in data directly to workspace. His example used a .csv file, which webread brings in beautifully (although I'm not sure how it assigns those field names to the structure 'w'). However, when I try webread on the following ascii file:

w=webread(www.essie.ufl.edu/~arnoldo/ocp6168/homework/lapreg.dat);

it brings it in as a long string (~83 kilocharacters), that needs to be parsed, reshaped, and converted (str2num), to work with numeric values. I just want a flag that tells MATLAB (webread) to expect the data to come in as double-precision numbers, not a long continuous string. I've looked up the documentation for webread and weboptions, but I didn't see a straightforward solution here. Anybody experienced with this who can point out my (dumb) mistake?

thanks.
Pete

This post was edited by Sarah Nakamoto on Jan, 2021
Peter,

Try to read it into a table instead:

w=webread('www.essie.ufl.edu/~arnoldo/ocp6168/homework/lapreg.dat',weboptions('ContentReader',@readtable))

though I note it will right now bring it into a table that is NX1 with 3 columns in the column itself. You can then extract the data into a double, turn it into 3 separate vectors, turn it into a 3 column table, ... Your choice.

--Loren

but I also am having trouble - running into a bug. Trying to work around it now...

This post was edited by Sarah Nakamoto on Jan, 2021
Here's the code I got to work:

options = weboptions('ContentReader',@(fn)readtable(fn, 'Format','%f %f %f',...
'HeaderLines',1,'ReadVariableNames',false));
w=webread(www.essie.ufl.edu/~arnoldo/ocp6168/homework/lapreg.dat, options);

%%
varnames = {'DayofYear', 'east', 'north'};
w.Properties.VariableNames = varnames;

By the way, a great example using this is on my blog - written by my colleague, Kelly.

http://blogs.mathworks.com/loren/2014/12/31/using-restful-web-service-interfa...

He makes good use of ContentReader. Check it out.