Shareware Grab Bag/Shareware Grab Bag.iso/090/cmln0386.arc/CROSSTH1.LTG

Text File | 1986-03-03 | 1KB | 46 lines

                           Listing  1.
Simulating a record strcuture in True BASIC containing numbers only.


! Define Selected Index function

DEF SI(REC_MAP$,P_VAR$)
! FIND POSITION OF VARIABLE IN RECORD MAP
LET PTR = POS(REC_MAP$,UCASE$(P_VAR$))
! EXTRACT INDEX
LET SI = VAL(REC_MAP$[PTR-2:PTR-1])
END DEF

!----------------------------------------------------------------

SUB INITIALIZE_CALC(MAP$, REC())

LET MAP$ = "01<TEMPERATURE>02<PRESSURE>03<VOLUME>04<RCONST>05<MOLES>"
! THE ALTERNATE ASSIGNMENT BELOW IS ALSO VALID
! LET MAP$ = "02<PRESSURE>01<TEMPERATURE>04<RCONST>03<VOLUME>05<MOLES>"

! INITILIZE WITH STP CONDITIONS
LET REC(SI(MAP$,"<TEMPERATURE>")) = 273 ! DEGREES KELVIN
LET REC(SI(MAP$,"<PRESSURE>")) = 1 ! ATMOSPEHERE
LET REC(SI(MAP$,"<RCONSTANT>")) = 0.082 ! UNIVERSAL GAS CONSTANT
END SUB

!----------------------------------------------------------------

SUB GET_VOLUME(MAP$,REC(),NUM_MOLE)

! ASSIGN ARRAY ELEMENT TO LOCAL VARIABLESèLET TEMP = REC(SI(MAP$,"<TEMPERATURE>")
LET PRESS = REC(SI(MAP$,"<PRESSURE>"))
LET R = REC(SI(MAP$,"<RCONSTANT>"))


! CALCULATE VOLUME
LET VOL = NUM_MOLE * R * TEMP / PRESS

! ASSIGN RESULT AND NUMBER OF MOLES TO PROPER ARRAY ELEMENTS
LET REC(SI(MAP$,"<VOLUME>")) = VOL
LET REC(SI(MAP$,"<MOLES>")) = NUM_MOLE

END SUB