measurement conversion

[Gary Atkinson]

Hi guys-

Maybe my brain is not working right today, but here goes.  I am getting height and weight data with two different units of measure in a Z segment in which I need to format to one unit of measure.  Here is an example–>

ZCR|||||||NY|||136^10.95|5^8.25

136^10.95 == the weight

5^8.25  == the height

136 is in kilograms

10.95 is in grams

5 meters

8.25 centimeters

So…I need the total weight in kilograms and total height in centimeters.  Any ideas on how to do this in TCL?  🙂

Topic

[Charlie Bursell]

If you divide grams by 1000 you get kilograms then just add together

Likewise if you multiply meters by 100 you get centimeters, then just add

[Gary Atkinson]

duh I was thinking it was more complicated than that 😳 Is there a tcl command to only allow two decimal points in a number?  Like 100.54545 turns into 100.54

[Charlie Bursell]

You can play around with the global value tcl_precision.  It defaults to 12.  It will round so you may want to set it to 3.  Try this

set sav $::tcl_precision   ;# Save current value

set ::tcl_precision  3      ;# change precision

expr 1.222222 + 3.333333

 => 4.56

# Set it back

set ::tcl_precision  $sav

BTW:  :: means global.  or you could just define tcl_precision as global

[Chris Williams]

Hey Gary,

Is this typical data? If these numbers are metric you’ve got a patient who weighs around 300 lbs and is about 16 ft tall.  😀  Just guessing, but a patient who weighs 136 lbs and is 5 ft 8 in sounds more realistic.

If you’re looking for a one-line precision solution you could take the result of your calculation and just format it with

[format “%0.2f” $value]

Cheers.

[Gary Atkinson]

LOL, those were numbers from a test case  😆 Thanks for the tip on using format command.

[Author]

Replies