Editing Guide to madagascar programs (section)

==sfwindow==
{| class="wikitable" align="center" cellspacing="0" border="1"
! colspan="4" style="background:#ffdead;" | Window a portion of a dataset. 
|-
! colspan="4" | sfwindow < in.rsf > out.rsf verb=n squeeze=y j#=(1,...) d#=(d1,d2,...) f#=(0,...) min#=(o1,o2,,...) n#=(0,...) max#=(o1+(n1-1)*d1,o2+(n1-1)*d2,,...)
|-
|  colspan="4" | <br>Other parameters from the command line are passed to the output (similar to sfput).
|-
| ''float  '' || '''d#=(d1,d2,...)''' ||   || 	sampling in #-th dimension
|-
| ''largeint'' || '''f#=(0,...)''' ||   || 	window start in #-th dimension
|-
| ''int    '' || '''j#=(1,...)''' ||   || 	jump in #-th dimension
|-
| ''float  '' || '''max#=(o1+(n1-1)*d1,o2+(n1-1)*d2,,...)''' ||   || 	maximum in #-th dimension
|-
| ''float  '' || '''min#=(o1,o2,,...)''' ||   || 	minimum in #-th dimension
|-
| ''largeint'' || '''n#=(0,...)''' ||   || 	window size in #-th dimension
|-
| ''bool   '' || '''squeeze=y''' ||  [y/n] || 	if y, squeeze dimensions equal to 1 to the end
|-
| ''bool   '' || '''verb=n''' ||  [y/n] || 	Verbosity flag
|}


<b>sfwindow</b> is used to window a portion of the dataset. Here is
a quick example: Start by creating some data.
<pre>
bash&#36; sfmath n1=5 n2=3 o1=1 o2=1 output="x1*x2" > test.rsf
bash&#36; < test.rsf sfdisfil
   0:             1            2            3            4            5
   5:             2            4            6            8           10
  10:             3            6            9           12           15
</pre>
Now window the first two rows:
<pre>
bash&#36; < test.rsf sfwindow n2=2 | sfdisfil
   0:             1            2            3            4            5
   5:             2            4            6            8           10
</pre>
Window the first three columns:
<pre>
bash&#36; < test.rsf sfwindow n1=3 | sfdisfil
   0:             1            2            3            2            4
   5:             6            3            6            9
</pre>
Window the middle row:
<pre>
bash&#36; < test.rsf sfwindow f2=1 n2=1 | sfdisfil
   0:             2            4            6            8           10
</pre>
You can interpret the <b>f#</b> and <b>n#</b> parameters as
meaning "skip that many rows/columns" and "select that many
rows/columns" correspondingly. Window the middle point in the dataset:
<pre>
bash&#36; < test.rsf sfwindow f1=2 n1=1 f2=1 n2=1 | sfdisfil
   0:             6
</pre>
Window every other column:
<pre>
bash&#36; < test.rsf sfwindow j1=2 | sfdisfil
   0:             1            3            5            2            6
   5:            10            3            9           15
</pre>
Window every third column:
<pre>
bash&#36; < test.rsf sfwindow j1=3 | sfdisfil
   0:             1            4            2            8            3
   5:            12
</pre>
Alternatively, <b>sfwindow</b> can select a window from the minimum and maximum
parameters. In the following example, we are
creating a dataset with <b>sfspike</b> and then windowing a portion of it
between 1 and 2 seconds in time and sampled at 8 miliseconds.
<pre>
bash&#36; sfspike n1=1000 n2=10 > spike.rsf         
bash&#36; sfin spike.rsf
spike.rsf:
    in="/var/tmp/spike.rsf@"
    esize=4 type=float form=native 
    n1=1000        d1=0.004       o1=0          label1="Time" unit1="s" 
    n2=10          d2=0.1         o2=0          label2="Distance" unit2="km" 
        10000 elements 40000 bytes
bash&#36; < spike.rsf sfwindow min1=1 max1=2 d1=0.008 > window.rsf
bash&#36; sfin window.rsf
window.rsf:
    in="/var/tmp/window.rsf@"
    esize=4 type=float form=native 
    n1=126         d1=0.008       o1=1          label1="Time" unit1="s" 
    n2=10          d2=0.1         o2=0          label2="Distance" unit2="km" 
        1260 elements 5040 bytes
</pre>
By default, <b>sfwindow</b> "squeezes" the hypercube dimensions
that are equal to one toward the end of the dataset. Here is an
example of taking a time slice:
<pre>
bash&#36; < spike.rsf sfwindow n1=1 min1=1 > slice.rsf
bash&#36; sfin slice.rsf 
slice.rsf:
    in="/var/tmp/slice.rsf@"
    esize=4 type=float form=native 
    n1=10          d1=0.1         o1=0          label1="Distance" unit1="km" 
    n2=1           d2=0.004       o2=1          label2="Time" unit2="s" 
        10 elements 40 bytes
</pre>
You can change this behavior by specifying <b>squeeze=n</b>.
<pre>
bash&#36; < spike.rsf sfwindow n1=1 min1=1 squeeze=n > slice.rsf
bash&#36; sfin slice.rsf 
slice.rsf:
    in="/var/tmp/slice.rsf@"
    esize=4 type=float form=native 
    n1=1           d1=0.004       o1=1          label1="Time" unit1="s" 
    n2=10          d2=0.1         o2=0          label2="Distance" unit2="km" 
        10 elements 40 bytes
</pre>