problem printing double format values

I am unable to print the values in double format, suppose if I have a value b=0.394944961213358 [1x1 double] it shows ??? Undefined function or method 'fprinf' for input arguments of type 'char'.

How can I round it to first four decimal values( as 0.3949) and print it to a file.

Thanks Ram

[ram m]

Sir I have one more question, I am trying to write the value of b for every loop to a file, but the it is updating the present value for next loop, How can I write the values in a column like a database

i=1

b =

i=2

b =

...

i = n

b=

Thanks

Answer 1

[Walter Roberson]

The function name is fprintf not fprinf

fprintf(fid, '%.4f', b)

[ram m]

thankyou

[Walter Roberson]

In response to the Comment you added to your question:

%before the loop

fid = fopen('YourOutputFile.txt', 'wt');

%inside the loop

fprint(fid, 'i = %d\nb = %.4f\n', i, b);

%after the loop

fclose(fid);

[ram m]

Thank you Sir

Answer 2

[Honglei Chen]

You missed a t, it's fprintf, not fprinf

[ram m]

thankyou