`set gxout stat `

d

- sends output to the terminal as opposed to a
plot or data output (e.g.,

```
set fwrite out.dat ; set gxout fwrite;
d rh
```

). Or the output goes to the script variable
`result`

which
can be parsed inside a script (see the `corr.gs`

GrADS
script)The output allows many statistical calculations to be made. Here's an example of opening up a global model file and looking at the 1000 mb relative humidity, statistically,

`ga-> set gxout stat `

ga-> d rh

Data Type = grid

Dimensions = 0 1

I Dimension = 1 to 145

J Dimension = 1 to 73

Sizes = 145 73 10585

Undef value = 1e+20

Undef count = 0 Valid count = 10585

Min, Max = 0.0610352 100.061

Stats(sum,sumsqr,n): 787381 6.35439e+07 10585

Stats(sum,sumsqr)/n: 74.3865 6003.2

Stats(sum,sumsqr)/(n-1): 74.3935 6003.77

Stats(sigma,var)(n): 21.6761 469.854

Stats(sigma,var)(n-1): 21.6771 469.898

Cmin, cmax, cint = 10 100 10

Let's break it down:

`Data Type = grid`

----- you have a grid
`Dimensions = 0 1`

----- the dimension type for the variable

`0`

- lon `1`

- lat `2`

- lev `3`

- time `1`

- not varying
`I Dimension = 1 to 145`

------ obvious

`J Dimension = 1 to 73`

`Sizes = 145 73 10585`

------- `10585`

is 145*73
or total number of points

`Undef value = 1e+20`

------- undefined value

`Undef count = 0 Valid count = 10585`

----- # of defined and
undefined points in the grid. Remember that if GrADS can't find
any data it returns undefs. This is useful for checking if you
have any data, `Valid count = 0`

means no...

`Min, Max = 0.0610352 100.061`

---- UHHH OHHHH! we have slight
supersaturation..

`Stats(sum,sumsqr,n): 787381 6.35439e+07 10585`

- This
should
be fairly obvious, sum = the simple sum of all **defined** points.

`sumsqr`

= sum of, in this case, `rh*rh`

and
`10585`

is `n`

.

`Stats(sum,sumsqr)/n: 74.3865 6003.2`

- Divide by
`n`

for convenience, the first number is the "biased"
mean...

`Stats(sum,sumsqr)/(n-1): 74.3935 6003.77`

- the so called
`unbiased`

mean (remove 1 degree of freedom), etc.

`Stats(sigma,var)(n): 21.6761 469.854`

- the standard
deviation
and variance "biased" (`n`

)

`Stats(sigma,var)(n-1): 21.6771 469.898`

- the standard
deviation and variance "unbiased" (`n-1`

)

`Cmin, cmax, cint = 10 100 10`

- What GrADS will use when
contouring.

`gridded`

and