# Question:Version Compatibility Maple 11 & Maple 12 - Ritz Method and Plate Vibration

## Question:Version Compatibility Maple 11 & Maple 12 - Ritz Method and Plate Vibration

Maple 11

Hello,

I am trying to use a worksheet developed by Professor Batista [ritz06.mws] for calculating plate vibration frequencies using the Ritz method, which is available from the Applications directory - Mechanical Engineering folder.  The worksheet was developed using Maple 12 and I am using Maple 11; a careful reading of the file didn't show any commands that were incompatible across the two versions and yet I am not able to solve the worksheet using the default inputs provided in the worksheet.  I have attached a PDF output of the file with the error message.  Any assistance that could be offered would be greatly appreciated.

Kind regards,

Wayne J. Bell AREVA NP, Inc. Charlotte, North Carolina

PS  I have attached the error output on the following page, but it will be necessary to run the worksheet using the file on website and if you have Maple 11, you should be able to reproduce the error message.  Professor Batista kindly suggested a workaround which was to evalf() the matrices used to calculate the eigenvalues and eigenvectors of the problem (you will see what I'm talking about in the worksheet), but this did not solve the problem.

#******************

# Solve

#*****************

calc(p1,p2,p3,rtol,opt); out: p, freqency factor 1..6;

Error, (in calc) invalid input: `simpl/Re` expects its 1st argument, x, to be

of type {algebraic, boolean}, but received Vector(18, {(1) =

129701.04714137+.0*I, (2) = 3590.630522216+.0*I, (3) = 2769.6837498878+.0*I,

(4) = 1503.5673712543+.0*I, (5) = 24.993309663606+.0*I, (6) =

329.18274748634+.0*I, (7) = 411.74547044233+.0*I, (8) = 107064.60866313+.0*I,

(9) = 104347.20924571+.0*I, (10) = 102994.44882996+.0*I, (11) =

99434.368829736+.0*I, (12) = 93624.726027461+.0*I, (13) = 88746.54742543+.0*

I, (14) = 87815.628196173+.0*I, (15) = 91480.160185542+.0*I, (16) =

90571.569647786+.0*I, (17) = 90862.044424587+.0*I, (18) = 86912.700974132+.0*

I}, data...

Error, missing operator or `;`

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