Re: [ferret_users] Re: command to plot error bar

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi - To define a variable with the same time axis as 
co2[x=@ave,l=1:12,y=-60:60@ave] and which computes

total_error = (SUM(ERROR)/N)**1/2

I think you'd want to compute the error sum over the same region you're 
using to plot CO2, x=1:360, y=-60:60. The Ferret commands would be

  yes? let xx = x[gx=CO2]
  yes? let yy = y[gy=CO2]
  yes? let nx = xx[x=@NGD]
  yes? let ny = yy[y=-60:60@NGD]

  yes? let nxy = nx * ny

  yes? let total_error = (error[x=@SUM,y=-60:60@SUM]/nxy)^0.5

( Note that some mail programs may translate the carat symbol before 0.5 
above, making a subscript.  The character is the carat symbol, the 
up-arrow. )

Then you can use this in the error bar script.

Ansley

Yogesh K. Tiwari wrote:

> Hi Ansley,
>
> Actually I have 2-d error data file which
> looks like
>
> name title   I         J         K         L
> ERROR       1:360     1:180    ...       1:12
>
> And I have CO2 data related to this error
>
> CO2        1:360     1:180     ...       1:12
>
> I am ploting CO2 curve in ferret
>
> plot  co2[x=@ave,l=1:12,y=-60:60@ave]
>
> Now I want to plot error bar using the data 1
> variable ERROR. This error data(data 1 ERROR)
> is (sigma)**2 . I want to calulate the total
> error like
>
> total_error = (SUM(ERROR)/N)**1/2
>
> here N I guess would be 180*360, am I right ?
>
> SO can you please suggest me how to calculate
> the total error in ferret for each month
> using this formula, this would be  error bar.
>
>
> And finally I want to plot error bar (total
> error) on the CO2 curve.
>
> For more clarification I wrote formula in
> word .doc file and I am sending you this
> little word file.
>
> Pls help.
>
> Many thanks in advance,
>
> Regards,
> Yogesh
>
>
>
>