First steps in Mathcad, HELP! with excel transition to it

[acastillo]

Hello PTC community,

I have recently been introduced to Mathcad 15, and understanding all the benefits of it, I got stacked in my first attempt of doing something.

I have a simple excel file (attached also), which I wanted to use as a training on Matchad, translating the content. What i encounter is a conceptual problem. I have literally no clue how to approach those simple calculation in Matchad. Can you please give me a hand in what will be the best approach?

I guess this is a typical issue for beginners, but I could not find in the helps files info about such a problem (maybe neither used to this PTC community website). Excuse me for maybe making too obvious questions. Thanks a lot in advance for all your help.

[ValeryOchkov]

See please the begin of this work in attach

[acastillo]

Hello Valery,

thanks for your input. I understand that I must use Matrixes to display tables, but I have two questions:

1- If I have to create 100 rows, do I have to type 1000 variable names? Or there's any shortcut to that?

2- I don't really need to see all results, I might just only need to graph them, how will be the approach then?

Thanks again for your help! I will try to start up a worksheet and post it soon 😉

[AndyWesterman]

One trick that you can try with XL is to use the Cell name function.

Depending on the version of XL you are using there is the possibility to make the formulae a little easier to read.

If you choose a cell Eg "C8" , it is possible to give it a readable name - Inner_Volume.

In previous versions of XL there was the capability to force this name to replace the cell reference in all formulae which gives you an easier way to see what the Mathcad equivalent equation should be.

Unfortunately this seems to have been lost in the ribbon update & formulae need to be manually updated.

    

As you are converting from XL to Mathcad, there are issues to be aware of.

In XL empirical formulae are 'normal' - the conversion of inner volume from 100 (L) to 0.1cubic meter is simple - divide the number by 1000 and in text note that this is now cubic meters.

The same is possible in Mathcad , but IMOH better to use the units capability - no conversions necessary , just define the format required.

The result for R_air and R_steam also show a scaling error & you will need to determine why.

probably due to a difference in the units used (e.g. gm/kg).

This is always an issue where an empirical formula is used - great care is required, but usually it can be resolved back to an equation that is valid with units. 

The notable exception to this is :

Here the units don't appear to give any possible option other than knowing that the temperature is expressed in Kelvin , so divide it out to give a unit-less number for calculation & then add the units at the end.

Complicated, but once you get the sheet working, it should be easier to understand (especially 6 months later...)

The other thing that XL can do that Mathcad (generally) does not is backward referencing.

There are a number of places where your XL sheet refers to values in non-sequential order.

So Cell O7 is calculated from Cell O15 / Cell O9

Mathcad calculates values in order, left - right , top - bottom.

calculations in the first 20 rows can easily be translated , the table will need to be re-arranged to ensure that the order is correct.

Hopefully these notes will give you a start in your conversion to Mathcad

Regards

   Andy