MathCad and amount of equations

Raiko · ‎Sep 25, 2009

Hello all,

MathCad appears to foul up its computation when the number of equations exceed a threshold; say more than twenty. I'm using mostly quite simple equations, no calculus or differential equations involved, so this shouldn't be a problem.
But the same equations repeated on a fresh sheet don't mess up as in cases when I'm putting more evaluations in one sheet. Such as comparing the performance of two different coatings. In one case MC gives out the standard deviation and the harmonic mean as zero but when splitting the data sets in two sheets the computation works ok.

Is it just me or is there a problem with MathCad?

Did anybody experience similar problems?

P.S.
I'm using MathCad 14. See the attached sheets.

TomGutman · ‎Sep 25, 2009

And what is the problem? You are displaying small numbers with only one decimal place, and the results are indeed zero to within one decimal place.
__________________
� � � � Tom Gutman

Raiko · ‎Sep 25, 2009

Hello Tom,

these are indeed small numbers (by the way, 0.014 isn't that small a number) and the problem is that MC delivers two different results. See the mean and the standard deviation in both sheets.

I've noticed before that MC seems to have a problem with longer "stuffed" sheets. Is this a general problem of MC or is there something I'm doing (systematically) wrong?

Raiko

P.S. Thanks for the hint Tom. For some reason, the results in MC were set to one decimal place and no exponential threshold whatsoever. This appears to be the culprit.

Raiko

StuartBruff · ‎Sep 25, 2009

On 9/25/2009 7:28:05 AM, raiko01 wrote:
== these are indeed small numbers (by the way, 0.014 isn't that small a number) and the problem is that MC delivers two different results. See the mean and the standard deviation in both sheets.

The expressions for μ_Gok are different - Y12_test.mcd has a double atan expression, whereas the other sheet doesn't. Changing the definition in Y12_test gives identical values for μ_Gok, and the mean & mean+stdev look about right on the plot.

== I've noticed before that MC seems to have a problem with longer "stuffed" sheets. Is this a general problem of MC or is there something I'm doing (systematically) wrong?

Can't tell. I haven't noticed it, and I've written some fairly long and involved worksheets. You'd need to post further examples to see if there a systemic problem and where it lies.

Stuart

ptc-1368288 · ‎Sep 25, 2009

>MathCad appears to foul up its computation when the number of equations exceed a threshold; say more than twenty <<br> _________________________

How much stuff do you think I have in some of my work sheets exceeding 80 pages ? Mathcad has no known limit, the limit will rather be your hard drive. Is it the joke of the day ?
jmG

StuartBruff · ‎Sep 25, 2009

On 9/25/2009 9:28:04 AM, jmG wrote:
>>MathCad appears to foul up its computation when the number of equations exceed a threshold; say more than twenty <<br> >_________________________
>
>How much stuff do you think I
>have in some of my work sheets
>exceeding 80 pages ? Mathcad
>has no known limit, the limit
>will rather be your hard
>drive. Is it the joke of the
>day ?
>jmG

Raiko is using M14, so your M11 experience may not apply.