How to format wkt (well known text string) as a normal string to build a webread input?

I am using an API to download some weather data, and I can get webread to work when I copy the example GET request, but I can't seem to figure out how to format the wkt portion of the request on my own.

For example, if I build the string like this, I will get a bad request error. If I copy the built string and replace the portion regarding wkt, then the code will run flawlessly. The equal sign is omitted, and the parenthesis are interpreted as some character value

% what wkt is supposed to look like in the string: &wkt=POINT(10+-50)
% what my wkt looks like in the string:            &wktPOINT%2810+-50%29

api_key = 'EXAMPLE_KEY';
wkt = 'POINT(10 -50)'; % <-- this is the issue
attributes = ['dni','dni','ghi'];
names = '2017';
utc = 'false';
leap_day = 'false';
interval = '30';
full_name = 'Example Name';
email = '[e-mail]';
affiliation = 'Example Institution';
reason = 'Test';
mailing_list = 'false';

api_base = 'https://developer.nrel.gov/api/nsrdb/v2/solar/psm3-download.json?';

data_out_struct = webread(...
    [ api_base '&api_key' api_key '&full_name' full_name '&email' email...
      '&affiliation' affiliation '&reason' reason '&mailing_list' mailing_list...
      '&wkt' wkt '&names' names '&attributes' attributes '&leap_day' leap_day...
      '&utc' utc '&interval' interval]...
      );

filename = 'Test_Downoad'
url = data_out_struct.outputs.downloadUrl;
websave(filename,url);

Answer 1

[Rik]

I suspect you need to apply percent encoding, as URLs are not allowed to contain spaces.

[Craig Atkinson]

I've tried to accept this answer several times yet the page errors out. Not sure why that is, but you did initally solve my problem

[Rik]

That is odd. When something errors on this site, I generally retry a few hours later.

If it keeps erroring out, feel free to flag this thread so site admins can take a look.

Anyway, glad to be of help.