Guide to Madagascar programs

sfheadercut: Zero a portion of a dataset based on a header mask.

sfheadercut mask=head.rsf < in.rsf > out.rsf

The input data is a collection of traces n1xn2,
mask is an integer array of size n2.

file	mask=		auxiliary input file name

sfheadercut is close to sfheaderwindow but instead of windowing the dataset, it fills the traces specified by the header mask with zeroes. The size of the input data is preserved.

Here is an example of using sfheaderwindow for zeroing every other trace in the input file. First, let us create an input file with ten traces:

bash$ sfmath n1=5 n2=10 output=x2+1 > input.rsf
bash$ < input.rsf sfdisfil
   0:             1            1            1            1            1
   5:             2            2            2            2            2
  10:             3            3            3            3            3
  15:             4            4            4            4            4
  20:             5            5            5            5            5
  25:             6            6            6            6            6
  30:             7            7            7            7            7
  35:             8            8            8            8            8
  40:             9            9            9            9            9
  45:            10           10           10           10           10

Next, we can create a mask with alternating ones and zeros using sfinterleave.

bash$ sfspike n1=5 mag=1 | sfdd type=int > ones.rsf
bash$ sfspike n1=5 mag=0 | sfdd type=int > zeros.rsf
bash$ sfinterleave axis=1 ones.rsf zeros.rsf > mask.rsf
bash$ sfdisfil < mask.rsf
   0:    1    0    1    0    1    0    1    0    1    0

Finally, sfheadercut zeros the input traces.

bash$ sfheadercut < input.rsf mask=mask.rsf > output.rsf
bash$ sfdisfil < output.rsf 
   0:             1            1            1            1            1
   5:             0            0            0            0            0
  10:             3            3            3            3            3
  15:             0            0            0            0            0
  20:             5            5            5            5            5
  25:             0            0            0            0            0
  30:             7            7            7            7            7
  35:             0            0            0            0            0
  40:             9            9            9            9            9
  45:             0            0            0            0            0

Guide to Madagascar programs