[chnrdu]

I want to make a transient simulation of a pipe. on one end, I make the pressure as a function respect to time and write to a file as:
(
t0 p0
t1 p1
...
tN pN
)
but when I compute it, there is a error:

Reading field p

--> FOAM FATAL IO ERROR : IOstream::check(const char* operation) : error in IOstream "inletPressure.dat" for operation Istream::operator()

file: inletPressure.dat at line 1.

Function: IOstream::check(const char* operation) const
in file: db/IOstreams/IOstreams/IOcheck.C at line: 54.

FOAM exiting

what about the error? How to correct?
Thanks in advance.

[mattijs]

1. is the file present?

2. what boundary condition are you using? timeVaryingUniformFixedValue?

Does it work if you remove the bracket pair? I think this b.c. reads an unformatted 2 column file to make it easy to use externally generated data.

[chnrdu]

Yes, I use the timeVaryingUniformFixedValue.

I removed the bracket pair. there is the same problem. You mean the unformatted 2 column file as binary file?

[mattijs]

Sorry, never used it. I found the actual reading gets done in sampling/lnInclude/graph.C where it constructs the graph from an Istream.

Looks like the format is
"title"
"x" "y"
0.0 54
0.1 24
0.2 35

or something similar.

[henry]

The format of the file read by timeVaryingUniformFixedValue is

(
t0 p0
t1 p1
...
tN pN
)

but the error message you get suggests that the file cannot be found, i.e. is not in the location you specify in the boundary condition details.

[chnrdu]

Thank u, H. Weller.

I find the error that u pointed out. I located it in the 0/p fold. i copy it to the caseroot fold. Now It works well.

[olivier]

Hi,
Foam don't accept this instruction.
How can I do this in Foam
-------------------
FILE *fp;
int i;
fp=fopen("filePr","r+");
for(i=0;i<=size;i++)
{
fscanf(fp,"%f %f %f %f",&pr[5*i],&pr[5*i+1],
&pr[5*i+2],&pr[5*i+3]);
}


fclose(fp);
-----------------------------
thanks

[mattijs]

IFstream str("filePr");

scalar a,b,c,d;

str>> a >> n >> c >> d;

[aurelia]

Hello

For postprocessing purpose, I am using ifstream to read a file and calculate something called A, which is then wroten in an other file


fileName fileV="v.dat";
OFstream VFile(fileV);
fileName fileC= "c.dat";
IFstream CFile(fileC);
char a;char b;
double T1;double T2;scalar C1x;scalar C1y;scalar C1z;scalar C2x;scalar C2y;scalar C2z;scalar A;
while(!CFile.eof() )
{ CFile>>T1>>a>>C1x>>C1y>>C1z>>b>>T2>>a>>C2x>>C2y>>C 2z>>b;
A= ...// Here it calculates A
VFile<< T2 << " "<<A<< endl;
}


It works (read, calculate and write) for all the value in the read-file but then I get the following error:

--> FOAM FATAL IO ERROR : Attempt to get back from bad stream

file: c.dat at line 124.

From function void Istream::getBack(token& t)
in file db/IOstreams/IOstreams/Istream.C at line 44.


I think that it doesn't understand that it is the end of the file, even with the .eof()
Should I close the file (... how?) to avoid this error?
Or should the read-file have something special at the end?

Thanks
Aurelia

[maka]

I have a file with the following format.

y1 u1 v1 w1
y2 u2 v2 w2
...
yn un vn wn

I know that one can read Field<t> from IStream but how can I read such mixed format to:
scalarField y;
vectorField u;

Is there a way to do it in OpenFOAM or should I write another graph class that accepts such format? thanks.

[kuczmas]

Hey Aurelia,
Did you manege to solve you problem? I have got the same error message, when trying to write my data into the file.

Cheers

[kuczmas]

Hey mattijs,

after using your code snippet

Originally Posted by mattijs

IFstream str("filePr");

scalar a,b,c,d;

str>> a >> n >> c >> d;

in my program I got the following error message:

--> FOAM FATAL IO ERROR: 
Attempt to get back from bad stream

file: filePr at line 1.

    From function void Istream::getBack(token&)
    in file db/IOstreams/IOstreams/Istream.C at line 38.

FOAM exiting

Do you know what's wrong and how to fix it?

[Bernhard]

Originally Posted by aurelia

--> FOAM FATAL IO ERROR : Attempt to get back from bad stream

I am encountering the same error message as above. Anyone who knows what I am doing wrong?

[Bernhard]

So, apparently, the problem is, the I am trying to read four values at once, like

file >> a >> b >> c >> d;

There error-message occurs on the second >> as far as I can see.

My work-around is as follows

file >> a;
if( !file.bad() )
{
    file >> b >> c >> d;
    // Everything else
}

which solves my problem.

I don't like the 'niceness' of this solution, so I am open for suggestions.