Guide to Madagascar programs

sfscale: Scale data.

sfscale < in.rsf > out.rsf axis=0 rscale=0. dscale=1.

To scale by a constant factor, you can also use sfmath.

int	axis=0		Scale by maximum in the dimensions up to this axis.
float	dscale=1.		Scale by this factor (works if rscale=0)
float	rscale=0.		Scale by this factor.

sfscale scales the input dataset by a factor. Here are some simple examples. First, let us create a test dataset.

bash$ sfmath n1=5 n2=3 o1=1 o2=1 output="x1*x2" > test.rsf
bash$ < test.rsf sfdisfil   
   0:             1            2            3            4            5
   5:             2            4            6            8           10
  10:             3            6            9           12           15

Scale every data point by 2:

bash$ < test.rsf sfscale dscale=2 | sfdisfil
   0:             2            4            6            8           10
   5:             4            8           12           16           20
  10:             6           12           18           24           30

Divide every trace by its maximum value:

bash$ < test.rsf sfscale axis=1 | sfdisfil
   0:           0.2          0.4          0.6          0.8            1
   5:           0.2          0.4          0.6          0.8            1
  10:           0.2          0.4          0.6          0.8            1

Divide by the maximum value in the whole 2-D dataset:

bash$ < test.rsf sfscale axis=2 | sfdisfil
   0:       0.06667       0.1333          0.2       0.2667       0.3333
   5:        0.1333       0.2667          0.4       0.5333       0.6667
  10:           0.2          0.4          0.6          0.8            1

The rscale= parameter is synonymous to dscale= except when it is equal to zero. With sfscale dscale=0, the dataset gets multiplied by zero. If using rscale=0, the other parameters are used to define scaling. Thus, sfscale rscale=0 axis=1 is equivalent to sfscale axis=1, and sfscale rscale=0 is equivalent to sfscale dscale=1.

Guide to Madagascar programs