CEE 4540 MathCAD help!
Here are the common confusions to have straightened out right away!
1. The different equal signs
a. The variable definition
type [shift] [:]
b. The boolean definition
use the boolean toolbar
"same" is a variable which holds the result of the boolean statement.
c. The statement (you ask mathcad to display a value)
type [=]
d. the arrow... the only definition sign to use in a programming bar.
like the arrow, you can't type the word 'return'. you have to use a shortcut or select it from the programming bar.
2. The best part of MathCAD... units!
SI units are default! Simply type your desired units to get the result you want in the little black box.
you can also look up units, or type in your own crazy units. To call the dialogue box to look up, double click on the black box.
I typed in [J] and [km] and MathCAD tried to help me out...
3. Careful about re-defining things. The little green underline shows that the variable is already in use. Try to avoid seeing this, or you may accidentally re-define something! If you are using a reference, especially an ADT reference, this can mess up your code.
oh no! I've redefined something.
so now the latest value is returned.
4. Make sure you remember the difference between local variables and other variables.
var.4 is a variable.
this variable is undefined!
5. The subscript: variable name versus vector
type variable [.] subscript
Return the value in row 2, column 1. Remember that MathCAD matrices are referenced starting at zero!
I use the matrix toolbar to select row or column.
6. Functions
I have defined a function. 'input' is a local variable in the function definition.
Now, I'll call the function by specifying the input as an actual value. Notice that the function is now on the definition end of the := sign.
7. References
Insert + Reference + Use relative reference path
This file especially has all of our accumulated knowledge about fittings and pipes. Don't reinvent the wheel!
Access to these files online:
http://designserver.cee.cornell.edu/aguaclaracode/
FYI: Past design teams have done a lot of the hard stuff already-- please use the library of resources we already have available to make your lives easier!
8. Using functions from references
This function is defined in the Fluid Functions file. I don't have to rewrite the function definition. I can directly use the function!
If functions are not working, some de-bugging steps are:
Optional extra stuff:
Graphing in MathCAD can be super nice!
Adding areas... [right click] insert + area
9. vector versus range variable
Within this programming bar, 'x' is a local variable that is a vector.
This is just returning the variable I defined above, but I could also type these numbers in manually.
Type value1 [,] value2 then hit the [m..n] key in the matrix toolbar.
This is a range variable, and it looks different!
10. Range variables used in graphs!
For some reason-- even though this looks just like the range variable-- it isn't a range variable! And it doesn't work! The moral of the story is: use range variables only in this context.
9. How to use vectorized code to multiply things element by element. This may speed things up when you have muptiple data sets to work with
The vectorize operator is in the matrix toolbar.
This isn't what we wanted... oops! Though this example is very simplistic, it will make things easier later on. Remember the vectorize operator when you have to do element by element multiplication.