Ask for help about the structure

[xiao]

Can anyone help me to find out what are the structure of 'DataTable' ?
Does loop the 14 layers or the 800*800 array first?
(NumX=NumY=800)
gridde and WriteHeader are two structures
Thank you~~~ :)
void WriteCloudStats (GRIDDEF *griddef, char *StatsDir, int month, int
year, short ****DataTable)
{

FILE *fptr[2];
int i,j,k,l;
char filename[200],command[250],monstr[5];
GRIDDEF header;

if(month < 10)
sprintf(monstr, "0%d",month );
else
sprintf(monstr, "%d",month) ;

sprintf(filenam e,"%s/CldYearlyStats_ %d_
%d.dat",StatsDi r,month,year);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");

for(i=0; i<2; i++){
if(fptr[i] != NULL){
WriteHeader(gri ddef,fptr[i]);
for(j=0; j<14; j++)fwrite(
&DataTable[i][j][0][0],
sizeof(short),
griddef->NumX*griddef->NumY,
fptr[i]
);
printf("Data is %d \n",&DataTabl e[i][j][0][0]);
fclose(fptr[i]);
}
}
}

[Jens Thoms Toerring]

xiao <li*********@gm ail.comwrote:

Can anyone help me to find out what are the structure of 'DataTable' ?
Does loop the 14 layers or the 800*800 array first?
(NumX=NumY=800)
gridde and WriteHeader are two structures

Since the information you give is rather incomplete and not always
consistent all of the following is not more than guesswork...

void WriteCloudStats (GRIDDEF *griddef, char *StatsDir, int month, int
year, short ****DataTable)
{
FILE *fptr[2];
int i,j,k,l;

'k' and 'l' are never used.

char filename[200],command[250],monstr[5];
GRIDDEF header;

'header' is never used

if(month < 10)
sprintf(monstr, "0%d",month );
else
sprintf(monstr, "%d",month) ;

This could be simplfied to a single line of

sprintf( monstr, "%02d", month );

sprintf(filenam e,"%s/CldYearlyStats_ %d_%d.dat",Stat sDir,month,year );
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");

for(i=0; i<2; i++){
if(fptr[i] != NULL){
WriteHeader(gri ddef,fptr[i]);

This probably writes whatever 'griddef' points to to the file

for(j=0; j<14; j++)fwrite(
&DataTable[i][j][0][0],
sizeof(short),
griddef->NumX*griddef->NumY,
fptr[i]
);

This obviously is supposed to write 14 times 'griddef->NumX *
griddef->NumY * sizeof(short)' bytes to the file, with the data
comming from memory starting at address '&DataTable[i][j][0][0]'
while 'j' is running from 0 through 13.

So you first get 'griddef' written into the file, then 14 repe-
titions of 800x800 data points.

But I am a bit worried if the compiler will like that since it
doesn't have any information that DataTable is a 4-domensional
array and about the index ranges. So it won't be able to calcu-
late where exactly DataTable[i][j][0][0] is. I guess you will
have to change the function to

void WriteCloudStats ( GRIDDEF * griddef,
char *StatsDir,
int month,
int year,
short DataTable[ 2 ][ 14 ][ 800 ][ 800 ] )

to allow the compiler to figure out where the data are. Or you have
to calculate the address yourself with

for ( j =0; j < 14; j++ )
fwrite( DataTable + ( 14 * i + j ) * griddef->NumX * griddef->NumY
sizeof( short ),
griddef->NumX * griddef->NumY,
fptr[ i ] );

while using

void WriteCloudStats ( GRIDDEF * griddef,
char *StatsDir,
int month,
int year,
short *DataTable )

That also has the advantage that it also works for other grid sizes
than 800x800.

The inner write loop could then further simplified by getting rid
of it altogether and writing all data in a single call

fwrite( DataTable + 14 * i * griddef->NumX * griddef->NumY
sizeof( short ),
14 * griddef->NumX * griddef->NumY,
fptr[ i ] );

Regards, Jens
--
\ Jens Thoms Toerring ___ [e-mail]
\______________ ____________ http://toerring.de

[Eric Sosman]

xiao wrote:

Can anyone help me to find out what are the structure of 'DataTable' ?
Does loop the 14 layers or the 800*800 array first?
(NumX=NumY=800)
gridde and WriteHeader are two structures
Thank you~~~ :)
void WriteCloudStats (GRIDDEF *griddef, char *StatsDir, int month, int
year, short ****DataTable)

Bad ASCII art:

short**** short*** short** short* short

DataTable -[0]
[1] -[1][0]
... [1][1] -[1][1][0]
... [1][1][1] -[1][1][1][0]
... [1][1][1][1]
...

{

FILE *fptr[2];
int i,j,k,l;
char filename[200],command[250],monstr[5];
GRIDDEF header;

if(month < 10)
sprintf(monstr, "0%d",month );
else
sprintf(monstr, "%d",month) ;

`sprintf(monstr , "%02d", month);' is easier. (Easier still:
leave it out altogether, since `monstr' is never used.)

sprintf(filenam e,"%s/CldYearlyStats_ %d_
%d.dat",StatsDi r,month,year);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");

You'd better hope that nothing goes wrong with either of
the cp commands, or you could wipe out the old data ... Since
you don't actually need the original copies (you overwrite them
immediately), why not just use the rename() function to change
the existing files' names? The benefit is that you can check
whether rename() succeeded or failed; there's no portable way
to do so with system().

for(i=0; i<2; i++){
if(fptr[i] != NULL){
WriteHeader(gri ddef,fptr[i]);
for(j=0; j<14; j++)fwrite(
&DataTable[i][j][0][0],
sizeof(short),
griddef->NumX*griddef->NumY,
fptr[i]
);

This is probably wrong, because it appears to assume that
the thing pointed to by DataTable is a four-dimensional array
in contiguous storage locations. (At least, it seems to assume
contiguity in the rightmost two dimensions; hard to tell for
sure without knowing what NumX and NumY signify.)

Arrays and pointers are not the same, even though there is
a good deal of common ground. I recommend that you study Section 6
of the comp.lang.c Frequently Asked Questions (FAQ) list at
<http://www.c-faq.com/>, and then return here if you still have
questions.

--
Er*********@sun .com

[William Pursell]

>
* * *if(month < 10)
* * * * sprintf(monstr, "0%d",month );
* * *else
* * * * sprintf(monstr, "%d",month) ;

How about:

sprintf( monstr, "%02d", month );

[xiao]

On Jul 18, 12:04 pm, William Pursell <bill.purs...@g mail.comwrote:

if(month < 10)
sprintf(monstr, "0%d",month );
else
sprintf(monstr, "%d",month) ;

How about:

sprintf( monstr, "%02d", month );

Thank you guys ~ Actually i compiled and run the program and it
generated a binary file that is 17920168 (800*800*14*2 bytes + 168
bytes header)
And I am trying to read the data stored in the binary file using IDL
and I am nit sure whether i should write like this intarr(14,800,8 00)
or intarr(800,800. 14) But neither of them show a right image.......
Sign......

[Chad]

On Jul 18, 10:04*am, Eric Sosman <Eric.Sos...@su n.comwrote:

xiao wrote:

Can anyone help me to find out what are the structure of 'DataTable' ?
Does loop the 14 layers or the 800*800 array first?
(NumX=NumY=800)
gridde and WriteHeader are two structures
Thank you~~~ :)

void WriteCloudStats (GRIDDEF *griddef, char *StatsDir, int month, int
year, short ****DataTable)

* * *Bad ASCII art:

* * * * short**** *short*** *short** * *short* * * * short

* * * * DataTable -[0]
* * * * * * * * * * *[1] -[1][0]
* * * * * * * * * * *... * *[1][1] -[1][1][0]
* * * * * * * * * * * * * * * ... * * [1][1][1] -[1][1][1][0]
* * * * * * * * * * * * * * * * * * * * *... * * * [1][1][1][1]
* * * * * * * * * * * * * * * * * * * * * * * * * * * * ...

{

* * *FILE *fptr[2];
* * *int i,j,k,l;
* * *char filename[200],command[250],monstr[5];
* * *GRIDDEF header;

* * *if(month < 10)
* * * * sprintf(monstr, "0%d",month );
* * *else
* * * * sprintf(monstr, "%d",month) ;

* * *`sprintf(monst r, "%02d", month);' is easier. *(Easier still:
leave it out altogether, since `monstr' is never used.)

* * *sprintf(filena me,"%s/CldYearlyStats_ %d_
%d.dat",StatsDi r,month,year);
* * *sprintf(comman d,"/bin/cp %s %s.arc",filenam e,filename);
* * *system(command );
* * *fptr[0] = fopen(filename, "w");
* * *sprintf(filena me,"%s/CldTotalStats_% d.dat",StatsDir ,month);
* * *sprintf(comman d,"/bin/cp %s %s.arc",filenam e,filename);
* * *system(command );
* * *fptr[1] = fopen(filename, "w");

* * *You'd better hope that nothing goes wrong with either of
the cp commands, or you could wipe out the old data ... *Since
you don't actually need the original copies (you overwrite them
immediately), why not just use the rename() function to change
the existing files' names? *The benefit is that you can check
whether rename() succeeded or failed; there's no portable way
to do so with system().

Maybe I'm not looking at it close enough, but how do you figure that a
failure with either cp could possibly wipe out the old data?

[Eric Sosman]

Chad wrote:

On Jul 18, 10:04 am, Eric Sosman <Eric.Sos...@su n.comwrote:

>xiao wrote:

>>[...]
sprintf(filenam e,"%s/CldYearlyStats_ %d_
%d.dat",Stats Dir,month,year) ;
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");

You'd better hope that nothing goes wrong with either of
the cp commands, or you could wipe out the old data ... Since
you don't actually need the original copies (you overwrite them
immediately) , why not just use the rename() function to change
the existing files' names? The benefit is that you can check
whether rename() succeeded or failed; there's no portable way
to do so with system().

Maybe I'm not looking at it close enough, but how do you figure that a
failure with either cp could possibly wipe out the old data?

If "cp foo foo.arc" fails, the original data in "foo" has
not been copied, and "foo" holds the only intact version of it.
If fopen("foo", "w") then succeeds, it truncates "foo" to zero
length and thus loses the only copy of the original data.

Since the program is going to write a new "foo" this might not
be a tragedy -- but I assume the O.P. placed some value on the old
contents, or he wouldn't have bothered with the "cp" steps.

--
Er*********@sun .com

[Chad]

On Jul 18, 2:26*pm, Eric Sosman <Eric.Sos...@su n.comwrote:

Chad wrote:

On Jul 18, 10:04 am, Eric Sosman <Eric.Sos...@su n.comwrote:

xiao wrote:
[...]
* * *sprintf(filena me,"%s/CldYearlyStats_ %d_
%d.dat",StatsD ir,month,year);
* * *sprintf(comman d,"/bin/cp %s %s.arc",filenam e,filename);
* * *system(command );
* * *fptr[0] = fopen(filename, "w");
* * *sprintf(filena me,"%s/CldTotalStats_% d.dat",StatsDir ,month);
* * *sprintf(comman d,"/bin/cp %s %s.arc",filenam e,filename);
* * *system(command );
* * *fptr[1] = fopen(filename, "w");
* * *You'd better hope that nothing goes wrong with either of
the cp commands, or you could wipe out the old data ... *Since
you don't actually need the original copies (you overwrite them
immediately), why not just use the rename() function to change
the existing files' names? *The benefit is that you can check
whether rename() succeeded or failed; there's no portable way
to do so with system().

Maybe I'm not looking at it close enough, but how do you figure that a
failure with either cp could possibly wipe out the old data?

* * *If "cp foo foo.arc" fails, the original data in "foo" has
not been copied, and "foo" holds the only intact version of it.
If fopen("foo", "w") then succeeds, it truncates "foo" to zero
length and thus loses the only copy of the original data.

* * *Since the program is going to write a new "foo" this might not
be a tragedy -- but I assume the O.P. placed some value on the old
contents, or he wouldn't have bothered with the "cp" steps.

--
Eric.Sos...@sun .com- Hide quoted text -

- Show quoted text -

Maybe I need to read the man pages when I get home from work. Right
now I'm having a hard time picturing how fopen can possibly hose foo
in this case.

[Eric Sosman]

Chad wrote:

On Jul 18, 2:26 pm, Eric Sosman <Eric.Sos...@su n.comwrote:

>Chad wrote:

>>On Jul 18, 10:04 am, Eric Sosman <Eric.Sos...@su n.comwrote:
xiao wrote:
[...]
sprintf(filenam e,"%s/CldYearlyStats_ %d_
%d.dat",Sta tsDir,month,yea r);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");
You'd better hope that nothing goes wrong with either of
the cp commands, or you could wipe out the old data ... Since
you don't actually need the original copies (you overwrite them
immediately) , why not just use the rename() function to change
the existing files' names? The benefit is that you can check
whether rename() succeeded or failed; there's no portable way
to do so with system().
Maybe I'm not looking at it close enough, but how do you figure that a
failure with either cp could possibly wipe out the old data?

If "cp foo foo.arc" fails, the original data in "foo" has
not been copied, and "foo" holds the only intact version of it.
If fopen("foo", "w") then succeeds, it truncates "foo" to zero
length and thus loses the only copy of the original data.

Since the program is going to write a new "foo" this might not
be a tragedy -- but I assume the O.P. placed some value on the old
contents, or he wouldn't have bothered with the "cp" steps.

Maybe I need to read the man pages when I get home from work. Right
now I'm having a hard time picturing how fopen can possibly hose foo
in this case.

In "w" mode, fopen() is defined to "truncate to zero length
or create text file for writing" (7.19.5.3p3). Either way, the
file is empty immediately after fopen() succeeds, and any data
that it might have contained beforehand is gone.

(It occurs to me that the O.P. ought to be using "wb" mode
instead of "w", since he's writing binary data rather than text
lines to the streams. Since he's using "/bin/cp" to make the
backup copies, though, he's probably using a POSIX system and
there's no distinction between text and binary streams. Still,
for cleanliness' sake it wouldn't hurt.)

--
Er*********@sun .com

[Barry Schwarz]

On 18 Jul 2008 16:43:45 GMT, [e-mail] (Jens Thoms Toerring)
wrote:

>xiao <li*********@gm ail.comwrote:

>Can anyone help me to find out what are the structure of 'DataTable' ?
Does loop the 14 layers or the 800*800 array first?
(NumX=NumY=800 )
gridde and WriteHeader are two structures

Since the information you give is rather incomplete and not always
consistent all of the following is not more than guesswork...

>void WriteCloudStats (GRIDDEF *griddef, char *StatsDir, int month, int
year, short ****DataTable)
{
FILE *fptr[2];
int i,j,k,l;

'k' and 'l' are never used.

> char filename[200],command[250],monstr[5];
GRIDDEF header;

'header' is never used

> if(month < 10)
sprintf(monstr, "0%d",month );
else
sprintf(monstr, "%d",month) ;

This could be simplfied to a single line of

sprintf( monstr, "%02d", month );

> sprintf(filenam e,"%s/CldYearlyStats_ %d_%d.dat",Stat sDir,month,year );
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[0] = fopen(filename, "w");
sprintf(filenam e,"%s/CldTotalStats_% d.dat",StatsDir ,month);
sprintf(command ,"/bin/cp %s %s.arc",filenam e,filename);
system(command) ;
fptr[1] = fopen(filename, "w");

> for(i=0; i<2; i++){
if(fptr[i] != NULL){
WriteHeader(gri ddef,fptr[i]);

This probably writes whatever 'griddef' points to to the file

> for(j=0; j<14; j++)fwrite(
&DataTable[i][j][0][0],
sizeof(short),
griddef->NumX*griddef->NumY,
fptr[i]
);

This obviously is supposed to write 14 times 'griddef->NumX *
griddef->NumY * sizeof(short)' bytes to the file, with the data
comming from memory starting at address '&DataTable[i][j][0][0]'
while 'j' is running from 0 through 13.

So you first get 'griddef' written into the file, then 14 repe-
titions of 800x800 data points.

But I am a bit worried if the compiler will like that since it
doesn't have any information that DataTable is a 4-domensional
array and about the index ranges. So it won't be able to calcu-

Actually, from the code presented we are guaranteed that DataTable is
in fact not an array. It must be a pointer to pointer to pointer to
pointer and is apparently simulating a 4D array.

>late where exactly DataTable[i][j][0][0] is. I guess you will
have to change the function to

void WriteCloudStats ( GRIDDEF * griddef,
char *StatsDir,
int month,
int year,
short DataTable[ 2 ][ 14 ][ 800 ][ 800 ] )

to allow the compiler to figure out where the data are. Or you have
to calculate the address yourself with

for ( j =0; j < 14; j++ )
fwrite( DataTable + ( 14 * i + j ) * griddef->NumX * griddef->NumY
sizeof( short ),
griddef->NumX * griddef->NumY,
fptr[ i ] );

while using

void WriteCloudStats ( GRIDDEF * griddef,
char *StatsDir,
int month,
int year,
short *DataTable )

That also has the advantage that it also works for other grid sizes
than 800x800.

The inner write loop could then further simplified by getting rid
of it altogether and writing all data in a single call

fwrite( DataTable + 14 * i * griddef->NumX * griddef->NumY
sizeof( short ),
14 * griddef->NumX * griddef->NumY,
fptr[ i ] );

Regards, Jens

Remove del for email