Demension Copy Parse Error

[hanson.alex]

When I try to copy the below equation from notepad into a sketch demension:

m_h*x4/(m_l^2)*(2*m_l - x4/NACA_c) + (m_t*NACA_c/.2*(.2969*sqrt(x4/NACA_c)-.1260*(x4/NACA_c)-.3516*(x4/NACA_c)^2+.2843*(x4/NACA_c)^3-.1015*(x4/NACA_c)^4))*cos(atan(m_h/(m_l^2)*(2*m_l - x4/NACA_c) + m_h*t/(m_l^2)*(-1/NACA_c)))

Inventor interprets it as:

 m_h * x4 / ( (m_l) ^ 2 ul ) * ( 2 ul * m_l - x4 / NACA_c ) + ( m_t * NACA_c / 0.2 ul * ( 0.2969 ul * sqrt(x4 / NACA_c) - 0.1260 ul * ( x4 / NACA_c ) - (0.3516 ul * ( x4 / NACA_c )) ^ 2 ul + (0.2843 ul * ( x4 / NACA_c )) ^ 3 ul - (0.1015 ul * ( x4 / NACA_c )) ^ 4 ul ) ) * cos(atan(m_h / ( (m_l) ^ 2 ul ) * ( 2 ul * m_l - x4 / NACA_c ) + m_h * t / ( (m_l) ^ 2 ul ) * ( -1 ul / NACA_c )))

NOTICE THE EXPONENT TERMS, ex:

(x4/NACA_c)^3   vs.     (0.2843 ul * ( x4 / NACA_c )) ^ 3 ul

Why is this happening? Is it an error or is there a reasonable explanation. In any case it is very cumbersome to use.

Note, when copying into the sketch equation curve this error does not happen.

[samiharada]

An equation you typed will be automatically modified to make it less ambiguous.

I believe this behavior is intentional, and the behavior has not been changed for 15+ years.

For example, when you type like:

  0.2  * ( x1 / x2) ^ 3

then it will be shown as

  (0.2 ul * ( x1 / x2 )) ^ 3 ul

Please noe that

 * The “^” operator has a lower precedence than multiplication
 * The extra parenthesis are added during redisplay, based upon the lower precedence that
   was determined during the initial parsing.
 * Inventor will add units to any unadorned term (number), hence all the extra ‘ul’ that get added.
   Inventor does this because it make the equation less ambiguous. 

Hope this helps, 

Thanks,

Sami Harada

Inventor Framework QA

Autodesk, Inc.

[hanson.alex]

That is odd...

The rest of the world recognizes:

1. exponents and roots
2. multiplication and division
3. addition and subtraction

What is the reasoning of Inventor's method? Is there a suggested method of
reformatting large equations?

--
Alexander Hanson
(509) 954-1868

University of Idaho
Mechanical Engineer Graduate

500 Queen Rd.
Moscow, ID 83843