Re: Need SOLVER Help in HP 19BII
- From: "Cyrille de Brébisson" <cyrille@xxxxxx>
- Date: Thu, 28 Jul 2005 14:16:22 GMT
Hello,
The only thing that pops in my mind is somehting along the lines of:
IF(S(MMBTU)):
IF(DTH<>0:
MMBTU-DTH*10:
THERM - MMBTU / .1):
IF(S(DTH):
MMBTU-DTH*10:
IF(S(THERM):
IF(MMBTU<>0:
THERM - MMBTU / .1:
IF(BTU <>0:
BTU - THERM x 99976.1244878:
THERM - GJ x 9.4804343)):
IF(S(BTU):
IF(THERM<>0:
BTU - THERM x 99976.1244878:
THERM - GJ x 9.4804343):
IF(THERM<>0:
THERM - GJ x 9.4804343:
BTU - GJ x 947817.0777492))))))
this assumes that the variables that you are not giving as input are set to
0 prior to starting the solver so the calcualtor can know which equatiuon to
use...
you can also rewrite the equation with logival operator such as:
IF((S(MMBTU) AND (DTH<>0)) OR (S(DTH) AND (MMBTU<>0)):
MMBTU-DTH*10:
IF((S(THERM) AND (MMBTU<>0)) OR (S(MMBTU) AND (THERM<>0)):
THERM - MMBTU / .1:
......
regards, cyrille
> "John A. Landry" <gyroCLIP-THISpilot001@xxxxxxxxxxxxx> wrote in message
> news:0i5ae1hc1311t9en2ljc5njvsmq7al7c85@xxxxxxxxxx
>> Greetings,
>>
>> I could use some help from the bright equation writing minds of this
>> group...
>>
>> I'm using several simple equations in the Solver function of a 19BII to
>> do
>> some simple energy unit conversions. In my work I regularly need to
>> quickly convert between mmBtu (1000 x 1000 x Btu's), Btu's, Therms,
>> Dekatherms (10 x Therms), and Gigajoules. To do this, I have the
>> following
>> equations set up in the Solver:
>>
>> (MMBTU - DTH x 10)=0
>> (THERM - MMBTU / .1)=0
>> (BTU - THERM x 99976.1244878)=0
>> (THERM - GJ x 9.4804343)=0
>> (BTU - GJ x 947817.0777492)=0
>>
>> To make a conversion, I first have to first go down through the list of
>> equations, select, and then execute the appropriate one. To make a
>> second
>> conversion, I have to back up to the equation list, reselect the
>> appropriate one, and execute, etc.
>>
>> My question is this:
>>
>> Is it possible to create a *single* equation which would contain *all*
>> the
>> unit variables above, yet would still allow me to enter only one known
>> and
>> then solve for one unknown variable? This would do away with the need
>> for
>> me to select the appropriate equation from the list each time.
>>
>> I guess what I'm specifically looking for is a way to have the Solver
>> function mimic the behavior of the built-in "Units" conversion menu of
>> this
>> calculator. In the built-in Units function of the 19BII, I'm presented
>> with a menu of many variables, to which I can store any single known unit
>> into one, and then solve for any other unknown.
>>
>> The Solver function of the 19BII has two commands which I think might be
>> helpful in this:
>>
>> An IF/THEN function: "IF(condition:expression1:expression2)"
>>
>> IF/THEN commands can be nested.
>>
>> The "Solve For" function: "IF(S(condition):expression1:expression2)"
>>
>> Regarding the "Solve For" function, the 19BII manual states: "The S
>> (solving for) function is used with the IF function to group equations
>> and
>> to specify the conditions under which one or the other is used."
>>
>> Here's an example:
>>
>> IF(S(WPAY):WPAY-WAGExHRS:SLPAY-SALRY-.05xSALES)=0
>>
>> "The S function appears within the IF function in the conditional
>> expression. In this case, the conditional expression is true if you
>> solve
>> for WPAY, and false if you solve for anything else."
>>
>> Any thoughts anyone? I'm sure it's pretty simple, but of course I
>> haven't
>> a clue how to make it happen.
>>
>> Thanks in advance,
>>
>> John L.
>
>
.
- References:
- Need SOLVER Help in HP 19BII
- From: John A . Landry
- Re: Need SOLVER Help in HP 19BII
- From: Graham Fraser
- Need SOLVER Help in HP 19BII
- Prev by Date: Re: Serie's problem
- Next by Date: Re: Serie's problem
- Previous by thread: Re: Need SOLVER Help in HP 19BII
- Next by thread: HP-71B
- Index(es):
Relevant Pages
|
