Why i get "Unexpected Matlab expression"?
显示 更早的评论
function [Drcode, timer, lat, lon, u, v] = read_drifter_1('cc1.dat' , '0');
%
% usage [Drcode, timer, lat, lon, u, v] = read_drifter_1(filename, plotflag)
% this routine reads the data from the .dat files produced by the Android
% Drifter application, and provides the data.
%
fid = fopen('cc1.dat');
A = fgetl(fid);
timer=[];
lat=[];
lon=[];
u = [];
v = [];
while ~feof(fid),
A = fgetl(fid);
s = findstr(A,' ');
N = length(s);
Rlat = str2num(A(s(1)+1:s(2)-1));
Rlon = str2num(A(s(2)+1:s(3)-1));
Ryy = str2num(A(s(5)+1:s(6)-1));
Rmm = str2num(A(s(6)+1:s(7)-1));
Rdd = str2num(A(s(7)+1:s(8)-1));
Rhh = str2num(A(s(8)+1:s(9)-1));
Rmin = str2num(A(s(9)+1:s(10)-1));
Rsec = str2num(A(s(10)+1:length(A)));
Rtime = datenum(Ryy, Rmm, Rdd, Rhh, Rmin, Rsec);
lat = [lat; Rlat];
lon = [lon; Rlon];
timer = [timer; Rtime];
end
%
% Start a quality control regarding times
% Sort the data in increasing time
[timer2, Itime] = sort(timer,'ascend');
lat2 = lat(Itime);
lon2 = lon(Itime);
% remove the data taken at exactly the same time (double records)
dt = diff(timer2);
J = find(dt > 0);
timer = timer2(J+1);
lat = lat2(J+1);
lon = lon2(J+1);
% %
fclose(fid);
Drcode = [];
if plotflag ~=0,
figure
plot(lon2, lat2,'.')
hold on
plot(lon, lat, 'o')
end
return
Christos
5 个评论
Christos Chatzilaou
2018-6-14
Try to define your function like this
function [Drcode, timer, lat, lon, u, v] = read_drifter_1(mystring , plotflag) %no ''
%do something with your input
fid = fopen(mystring);
...
end
and then you can call it:
read_drifter('cc1.dat',0)
Christos Chatzilaou
2018-6-14
Christos Chatzilaou
2018-6-14
采纳的回答
Guillaume
2018-6-14
It looks like you haven't really understood how to define functions and how to use them.
The signature of a function is
function [outputvar1, outputvar2, ...] = functionname(inputvar1, inputvar2, ...)
where outputvarx and inputvarx are variable names that you then use in the body of your function. They must be variable names, you can't replace these by actual value. Strangely enough you've got it right in the function documentation. Your function signature should be
function [Drcode, timer, lat, lon, u, v] = read_drifter_1(filename, plotflag)
When you want to use that function, you don't go and edit that signature and write the values to use in there. Instead you call that function from the command line, a script, or another function. For example, if you want to use that function with the inputs 'cc1.dat' and 0, you'll call it with the line:
read_drifter_1('cc1.dat' , 0)
or if you want to see the outputs:
[somename, someothername, anothername, outputforlon, outputforu, outputforv] = read_drifter_1('cc1.dat' , 0)
Some other notes:
- It's not an error but the return at the end of the function is unnecessary. Remove it.
- The value you pass for plotflag should be logical or numerical, not a char array. You're meant to pass either true, false, 0, or 1, but not '0' or '1'. Both '0' and '1' would have the same effect as if you've passed true.
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Mathematics and Optimization 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
