function saveplotlycredentials(username, api_key, stream_ids)

% Save plotly authentication credentials.

% Plotly credentials are saved as JSON strings

% in ~/.plotly/.credentials

% catch missing input arguments

if nargin < 2

error('plotly:savecredentials', ['Incorrect number of inputs. ' ...

'Please save your credentials as follows: >> ' ...

'saveplotlycredentials(username, api_key,[optional]' ...

'stream_ids)']);

end

% if the credentials file exists, then load it up

try

creds = loadplotlycredentials();

catch

creds = struct();

end

% Create the .plotly folder

userhome = getuserdir();

plotly_credentials_folder = fullfile(userhome, '.plotly');

plotly_credentials_file = fullfile(plotly_credentials_folder, '.credentials');

[status, mess, messid] = mkdir(plotly_credentials_folder);

if (status == 0)

if (~strcmp(messid, 'MATLAB:MKDIR:DirectoryExists'))

error('plotly:savecredentials', ['Error saving ' ...

'credentials folder at ' plotly_credentials_folder ...

': ' mess ', ' messid '. Get in touch at ' ...

'chris@plot.ly for support.']);

end

end

fileIDCred = fopen(plotly_credentials_file, 'w');

if (fileIDCred == -1)

error('plotly:savecredentials', ['Error opening credentials ' ...

'file at ' plotly_credentials_file '. Get in touch at ' ...

'chris@plot.ly for support.']);

end

switch nargin

case 2

creds.username = username;

creds.api_key = api_key;

case 3

creds.username = username;

creds.api_key = api_key;

creds.stream_ids = stream_ids;

end

creds_string = m2json(creds);

%write the json strings to the cred file

fprintf(fileIDCred, '%s', creds_string);

fclose(fileIDCred);

%signin using newly saved credentials

signin(username, api_key);