Variables and data table

Question

Variables and data table

haynewp (Structural)

(OP)

7 Feb 05 11:37

I want to start using Mathcad instead of Excel but I am having trouble figuring out how to do something in Mathcad.

Usually in Excel, I have several variables that have a lot of data associated with each one. For instance, I would create a table that looks like this in excel:

SHAPE:             Ag     rx      ry     rz
L3x3x3/16    1.090    0.933    0.933    0.596
L3x3x1/4    1.440    0.926    0.926    0.592
L4x4x1/4    1.930    1.250    1.250    0.795
L4x4x5/16    2.400    1.240    1.240    0.791

Then I would have a pulldown menu that contains the variables: L3x3x3/16  L3x3x1/4  L4x4x1/4  L4x4x5/16.

Then based on the variable I choose, all the other properties are automatically assigned somewhere in the spreadsheet(Ag, rx, ry, rz) from the "index" and "match" functions.

Is there something equivalent to this in Mathcad? I don't want to have to type in all the different properties each time for each variable.

IRstuff (Aerospace) · Answer 1 · 2005-02-07 12:38:13

The analogous thing can be done in Mathcad using Active Components. You'd have similar pulldown menus to select the properties and then do lookup's or other processing to the final result. If you hunt around the Mathcad Library and/or the Mathcad Collaboratory, you can find examples:

http://collab.mathsoft.com/~Mathcad2000
http://www.mathcad.com/resources/mathcad_files/

TTFN

haynewp (Structural) · Answer 2 · 2005-02-08 18:04:48

Okay, I inserted my data as an "input table" which is being read from an outside text file. So I am just getting raw numbers which are in the form of an array which I am able to access each number indiviudally wherever I need to. So that is great.

But I need to assign units to each data value that I am getting from the array, and the units will vary (some numbers represent areas, others weights, etc.) Everytime I try to assign a unit value I get a new converted number that comes out unitless.

For example I am trying to place "in" (inches) in the placeholder behind the data number "3" that I am accessing from the array. I put "in" in the placeholder and the number turns into "36 in/ft".

IRstuff (Aerospace) · Answer 3 · 2005-02-08 18:30:20

If units don't convert correctly, it's most likely that you've redefined a built-in unit somewhere in your sheet that's honking up the unit conversion.

TTFN

haynewp (Structural) · Answer 4 · 2005-02-09 09:42:12

I think I figured out what to do. When I access a number from the array, I have to multiply the dimension out to the side.

For example, my data table is an array named "A". I am trying to access the number "5" from the array which is in position (1,1).

Then A(1,1)*IN^2=5IN^2

I mulitiplied the expression A(1,1) by IN^2 to get 5IN^2.

IRstuff (Aerospace) · Answer 5 · 2005-02-09 12:10:45

RE: Variables and data table

IRstuff (Aerospace) 9 Feb 05 12:10

Sounds right.

TTFN

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Variables and data table