Defining User Variables
ComputeList File Format
15-4
Using the LI-6400
15
In general, the format for each item defined in a ComputeList is
##<ID number>[Fmt Code] "<label>" "<description>"
"<equation>"
The ID number
The ## marks the start of a definition of a user variable, and is followed by a
positive integer that serves as the ID number of that variable. This ID number
is quite arbitrary, but it must be an integer between 1 and 32767. The ID num-
bers must be unique in the file, so if you are adding a new variable, give it a
unique number. These numbers are used by OPEN to identify the variable in
display format files, real time graphics plot definitions, log lists, etc.
There are no consequences of duplicating a user variable number other than
confusion, because only the first occurrence of a particular variable ID will
actually be used; the duplicate(s) will be computed but inaccessible.
Format Code
Immediately following the ID number is the optional format code. The de-
fault format for displaying and logging user computations is to use 3 signifi-
cant digits, resulting in values such as
1.23
0.0123
-1.23E+7
You can specify other formats by appending a format specifier to the ID
##10 "(U/S)" "flow:area ratio"
" flow_um / area_cm2 / 100.0"
##20 "Trans" "Transpiration (mol/m2/s)"
" #10 * (h2o_2_mm - h2o_1_mm) / (1000.0 - h2o_2_mm)"
##21 "Trmmol" "Transpiration (mmol/m2/s)" " #20 * 1E3"
##23 "Cond" "Stomatal cond. (mol/m2/s)"
" StdCond(#20, Tleaf_c, condBL_mol, press_kPa, h2o_2_mm)"
Figure 15-2. A sample of a Compute List file, including the equations for transpiration and conductance.
Summary of Contents for LI-6400
Page 1: ...Using the LI 6400 Portable Photosynthesis System ...
Page 15: ...Part I The Basics ...
Page 16: ......
Page 174: ...Making Measurements Answers to Questions 4 56 Using the LI 6400 4 ...
Page 175: ...Part II Useful Details ...
Page 176: ......
Page 200: ...Standard Tools Power ON Hooks 5 24 Using the LI 6400 5 ...
Page 214: ...Real Time Data Real Time Graphics 6 14 Using the LI 6400 6 ...
Page 234: ...Environmental Control Light Control 7 20 Using the LI 6400 7 ...
Page 244: ...Light Sensor Considerations Gallium Arsenide Phosphide GaAsP Sensor 8 10 Using the LI 6400 8 ...
Page 288: ...Data Logging Making Your Own AutoPrograms 9 44 Using the LI 6400 9 ...
Page 289: ...Part III Working With Files ...
Page 290: ......
Page 312: ...The LPL File System Troubleshooting 10 22 Using the LI 6400 10 ...
Page 340: ...Downloading Files Using a Data Capture Program 11 28 Using the LI 6400 11 ...
Page 375: ...Part IV Configuration Issues ...
Page 376: ......
Page 420: ...Defining User Variables Old Style vs New Style 15 18 Using the LI 6400 15 ...
Page 454: ...Using an Energy Balance Further Reading 17 12 Using the LI 6400 17 ...
Page 455: ...Part V Maintenance Troubleshooting ...
Page 456: ......
Page 572: ...Troubleshooting Useful Information 20 46 Using the LI 6400 20 ...
Page 593: ...Part VI Programming ...
Page 594: ......
Page 622: ...Programming with LPL Compiler Directives 22 28 Using the LI 6400 22 ...
Page 846: ...Index I 16 Using the LI 6400 ...