Decimal Places

[Valyence]

Hi I am very new to Matchcad and i am having trouble getting Mathcad to display to correct number of decimal places. What i have read says that by default Mathcad should display 3 decimal places. Whenever I perform calculations I am getting something like 21 decimal places. I looked in the help files and it says to go to format,result, and then change the decimal places. The problem is that mine is at the default of three decimal places so this leaves me stuck on where to go because it displays 21 decimal places. Any help would be greatly appreciated.

Thanks

Matt

[nas0k]

A simple solution would be to select "float" (floating point evaluation) from the Symbolic toolbar; "float, 6" works close to what you may accept.

Norm

[Valyence]

Yes thanks for the help. I actually figured out what the problem was. I had to apply those results to the symbolic results as well. Thanks for leading me in the right direction.

[RichardJ]

A simple solution would be to select "float" (floating point evaluation) from the Symbolic toolbar; "float, 6" works close to what you may accept.

You should be aware that if you use the float keyword it does not only change the display precision of the result, is changes the the precision used for the calculations.

[RichardJ · Accepted solution]

Mathcad does both symbolic math and numeric math. You should be using numeric math.

[Valyence]

Thanks for your answer that was a lot of help. Whenever i am giving a guess answer does it matter that i have no idea what the answer is going to be? It looked like you put in some random values for your guess is that right? Also whenever i solved it symbolicly i was able to go into format,result and tell it to apply those results to symbolic answers as well and this gave me the correct amount of decimal places. Is there any danger that when i do that i wont get correct answers for future calculations.

Again thanks for the help.

Matt

[RichardJ]

Thanks for your answer that was a lot of help. Whenever i am giving a guess answer does it matter that i have no idea what the answer is going to be? It looked like you put in some random values for your guess is that right?

Yes, it does matter. It has to be reasonably close, and if the answer is going to be complex then the guess must be complex. How close "reasonably close" is depends on the problem. If it's too far off it may converge to the wrong solution, or possibly fail to converge altogether.

Also whenever i solved it symbolicly i was able to go into format,result and tell it to apply those results to symbolic answers as well and this gave me the correct amount of decimal places. Is there any danger that when i do that i wont get correct answers for future calculations.

There is no danger of that. The result formatting affects only what is displayed, not how the number is stored internally or how it is used in calculations.

[MikeArmstrong]

Beat me to it.

Mike

[MikeArmstrong]

Whenever i am giving a guess answer does it matter that i have no idea what the answer is going to be? It looked like you put in some random values for your guess is that right?

Most of the time the guess values can be random, but be aware that if they are too far from the actual result, sometimes a solution is not found.

Also whenever i solved it symbolicly i was able to go into format,result and tell it to apply those results to symbolic answers as well and this gave me the correct amount of decimal places. Is there any danger that when i do that i wont get correct answers for future calculations.

No, formatting the results will only have an effect on the results

Mike

[ValeryOchkov]

I use not Decimal Places (afret decimal separator . or ,) but total number of digits in result.

One example:

http://twt.mpei.ru/MCS/Worksheets/rbtpp/eng/tab6.xmcd