what is different between fget1 and fread ?

path='F:\多光谱材料\2\2.hdr';

>> fnm='2.hdr';
>> I=enviread(path,fnm);
??? Error using ==> fgetl at 44
Invalid file identifier.  Use fopen to generate a valid file identifier.

Error in ==> enviread>read_envihdr at 190
    line = fgetl(fid);

Error in ==> enviread at 16
info=read_envihdr(hdrfile);

Answer 1

[Mohammad Abouali]

I don't think enviread is a function provided by mathworks. It appears it is something that users have provided.

Try multibandread() function of matlab to read ENVI files. I use this function when I am reading ENVI files and it works very well. If you want some instruction on how to use it to read ENVI files, the following is a good resource.

http://www.ehu.eus/ccwintco/uploads/d/dc/LoadHypercubesMatlab.pdf

[yanjie qi]

thank you,sir

[yanjie qi]

SIR,

I want to convert the data(2-array ) into an image? but the elements are too many, can you give me some suggestions, appreciate on it

[Mohammad Abouali]

I am not sure if I understand thequestion

Answer 2

[Jan]

Do not overwrite the important Matlab function path with a variable. Although this will not be the reason of the error, it is a bad idea and might cause severe problems during debugging.

The error means, that the file could not be opened. Most likely the file or folder name is not correct.

I do not see a relation between the error message and the title "difference between fget1 and fread". As the docs explain, fgetl reads a complete line from a text file, while fread reads a specified number of elements from a text or binary file in a specified format.

[yanjie qi]

thank you, sir

I know that path is a matlab variable, this is not the main error.I tried to put .hdr .raw and M file togeter,and ran it. This time it with such error, I will show you :

??? Undefined function or method 'fget1' for input arguments of type 'double'.

Error in ==> enviread>read_envihdr at 190 line = fget1(fid);

Error in ==> enviread at 16 info=read_envihdr(hdrfile);

also I load the original file.

[Jan]

Do you see, that your command is called "fetg1" with a trailing "one" not an lower-case "L"? The attached code uses "fgetl" with an L. So you error message does not match the code - please do not confuse the readers with such jokes.

The code is instable. The comparison " if varargin{2}=='date' " will fail with an error, if the 2nd input does not have 4 characters. Use this instead:

if strcmp(varargin{2}, 'date')

The eval s are such ugly!

eval(['info.',param,' = ''',value,''';'])

What about:

info.(param) = value;