[ferret_users] inconsistent behaviour trying to use min to find location.

[rdbriggs <rdbriggs@xxxxxx>]

Hello,

In the past I've used the

let vmax = v[x=@max,y=@max]

and

let xloc = v[x=@loc:`vmax`]

commands to successfully find the location of the minimum. But this time I have a problem, can anyone tell me what I am doing wrong?

My functions are FUNDHS, FUNDHS50

! get min
LET outDHS = funDHS[T=@MIN]
LET outDHs50 = funDHs50[T=@MIN]

! and time it occurs
LET TDHS= funDHS[T=@LOC:`outDHS`]
LET TDHs50 = funDHs50[T=@LOC:`outDHs50`]

LIST outDHS, outDHS50, TDHs, TDHs50
             DATA SET: ./rreconHs.dat
             T: -120.5 to 0.5
 Column  1: OUTDHS is FUNDHS[T=@MIN]
 Column  2: OUTDHS50 is FUNDHS50[T=@MIN]
 Column  3: TDHS is FUNDHS[T=@LOC:0.7081349]
 Column  4: TDHS50 is FUNDHS50[T=@LOC:27.53873]
          OUTDHS  OUTDHS5  TDHS  TDHS50
I / *:     0.7081   27.54 -10.00   ....


------>  SoTDHS  worksTDHS50  does not ?

The output from my two functions are

yes? list FUNDHS, FUNDHS50

15    / 106:     50.    163.
-14    / 107:     33.    130.
-13    / 108:     20.    109.
-12    / 109:     10.    104.
-11    / 110:      3.     32.
-10    / 111:      1.     28.<  ------ I want to automatically identify this time
-9     / 112:      2.     28.
-8     / 113:      7.     32.
-7     / 114:     16.     41.
-6     / 115:     28.     52.
-5     / 116:     44.     68.
-4     / 117:     64.     87.
-3     / 118:     88.    110.
-2     / 119:    115.    137.
-1     / 120:    145.    167.
0      / 121:    180.    201.
yes? list FUNDHS, FUNDHS50


improving the precision
yes? list/form=(2(F9.4)) FUNDHS, FUNDHS50

 33.1926 130.2298
  19.8315 108.5893
  10.4672 104.3460
   2.9604  32.1601
   0.7081  27.5387<------ these are the mins
   2.1548  28.4311
   7.2379  32.3409
  15.9903  40.5858
  28.3927  52.3871
  44.4533  68.0784
  64.1537  86.9202
  87.5170 109.8389
 114.5442 136.8729
 145.2063 166.8670
 179.5263 200.7330


yes? list FUNDHS50[T=@LOC:27.53873]
             VARIABLE : T of 27.54 in ((HS_ADJDHS50 - HSOBS)/SIGHS50)^2 + ((TAX-TOBS) / TOBS_SIG)^2
             FILENAME : rreconHs.dat
             T        : -120.5 to 0.5 (location of 27.54)
        ....
yes? list FUNDHS50[T=@LOC:28]
             VARIABLE : T of 28 in ((HS_ADJDHS50 - HSOBS)/SIGHS50)^2 + ((TAX-TOBS) / TOBS_SIG)^2
             FILENAME : rreconHs.dat
             T        : -120.5 to 0.5 (location of 28)
         -10.10

yes? list outDHS50
             VARIABLE : FUNDHS50[T=@MIN]
             FILENAME : rreconHs.dat
             T        : -120.5 to 0.5
          27.54
yes? list FUNDHS50[T=@LOC:27.53]
             VARIABLE : T of 27.53 in ((HS_ADJDHS50 - HSOBS)/SIGHS50)^2 + ((TAX-TOBS) / TOBS_SIG)^2
             FILENAME : rreconHs.dat
             T        : -120.5 to 0.5 (location of 27.53)
        ....

Any ideas what is going on here ?

Regards,

Rob


--
Ph.D candidate Glacial Systems Dynamics

C4059
Department of Physics and Physical Oceanography
Memorial University of Newfoundland, St. John's
NL, A1B 3X7, Canada

Phone   : 001 (709) 864-2407
Email   : rdbriggs@xxxxxx
Website : http://www.physics.mun.ca/~rdbriggs/


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