I am looking for a workaround to an error I am getting in an m-file. It is from the Matlab Cenral File exchange: http://www.mathworks.com/matlabcentral/fileexchange/25764-windcan
The m-file downloads climate data from a website and names it, then appends only the data the user needs its own file.
function windcan % COPYRIGHT (C) 2009, JOSH WIEBE
% DISTRIBUTED "AS IS" UNDER THE BSD SOFTWARE LICENCE, SEE LICENCE FILE
% THIS PROGRAM USES THE URLWRITE COMMAND TO DOWNLOAD HOURLY CLIMATE DATA FROM THE ENVIRONMENT CANADA WEBSITE
% WIND DATA IS THEN PLUCKED FROM THE DOWNLOADED FILES AND SAVED IN A CSV FILE WHICH CAN LATER BE ANALYSED
% IN WRPLOT OR A SIMILAR PROGRAM, OUTPUT FILE COLUMN ORDER IS YEAR, MONTH, DAY, HOUR, DIRECTION, SPEED
fprintf ('See http://climate.weatheroffice.ec.gc.ca/climateData/canada_e.html \n select location, scroll to link to "bulk data", station id appears in menu bar. \n e.g. Ottawa = 4337 \n'); stationid = input('Enter Station ID '); year1 = input('Enter start year '); year2 = input('Enter end year '); month1 = input('Enter start month, enter 1 for January '); month2 = input('Enter end month '); filename = input('Enter output file name: ', 's'); N = (month2-month1+1)*(year2-year1+1); year = year1; month = month1; % ROUTINE TO DOWNLOAD CLIMATE DATA
for i=1:N urlwrite(sprintf('http://www.climate.weatheroffice.ec.gc.ca/climateData/bulkdata_e.html?timeframe=1&Prov=XX&StationID=%i&Year=%i&Month=%i&Day=1&format=csv&type=hly', stationid, year, month), sprintf('%i%i%i.csv', stationid, year, month)); if month < month2; month = month +1; else month = month1; year = year+1; end %if
end %for
% RESET PARAMETERS, ASSIGN NAME FOR OUTPUT FILE
year = year1; month = month1; s = 'YEAR, MONTH, DAY, HOUR, DIRECTION, SPEED (m/s)'; dlmwrite(filename, s, ''); % ROUTINE TO PLUCK WIND DATA FROM DOWNLOADED CLIMATE DATA
for i=1:N temp=dlmread(sprintf('%i%i%i.csv', stationid, year, month), ' "," '); % ' "," ' USED AS DELIMITER BECAUSE THE .CSV FILE USES QUOTATION MARKS AROUND TEXT FIELDS
L=length(temp); yearI = temp (15:L, 6); % START IMPORT AT ROW 15, COLUMN 6 IS YEAR
monthI = temp (15:L, 9); dayI = temp (15:L, 12); hourI = temp (15:L, 15); winddir = temp (15:L, 36); windspd = temp (15:L, 42); winddat(:,1) = yearI; % PUT DATA INTO ONE MATRIX
winddat(:,2) = monthI; winddat(:,3) = dayI; winddat(:,4) = hourI; winddat(:,5) = winddir*10; % WIND DIRECTION IN 10 DEGREE BINS
winddat(:,6) = windspd*0.278; % CONVERT WINDSPEED FROM KPH TO MPS
dlmwrite(filename, winddat, ',' , '-append'); %APPEND MATRIX "WINDDAT" TO OUTPUT FILE
clear winddat; %CLEAR THE WINDDAT VARIABLE ONLY
if month < month2; month = month +1; else month = month1; year = year+1; end %if end %for end %function
The code for downloading and naming the files works well – the files are downloaded and name correctly and the new file is created. The last section for retrieving the columns to write to the new file gives this error:
??? Error using ==> dlmread at 75 DELIMITER must be a single character.
Error in ==> windcan at 39 temp=dlmread(sprintf('%i%i%i.csv', stationid, year, month), ' "," '); % ' "," ' USED AS DELIMITER BECAUSE THE .CSV FILE USES QUOTATION MARKS AROUND TEXT FIELDS
First off, why would the author think that ' "," ' would work as a delimiter with dlmread to trick it to importing dates? Can this be done successfully?
Secondly, is there an replacement for dlmread for reading in the file columns without changing the whole naming and looping system? i.e. going to a system that creates a date vector out of the file names and incrementing rather than using the i=1:N file system.
I like the simplicity of the code and the naming system and would like to stay with it if possible. Any help would be greatly appreciated.
Best Answer