1. Click a region to configure, or click outside a region to apply the calculation settings to all the regions in your worksheet.
2. On the Calculation tab, in the Worksheet Settings group, activate or deactivate the following options from the Calculation Options list:
◦ Approximate Equality—Controls the standard used in Boolean comparisons and truncation functions. When this option is not active, two numbers must differ by less than the maximum accuracy of your computer's floating point processor to be considered equal. Numbers from −10-307 to 10-307 are considered to be 0. When truncating numbers, all decimal places are used in determining the floor, ceiling, or truncated value of a number.
When this option is active, the absolute value of the difference between two numbers divided by their average must be < 10-12 for them to be considered equal, and only the first 12 decimal places are used in truncation.
◦ ORIGIN in Strings—Controls the integer associated with the first character in a string. With this option, string functions consider the worksheet value for ORIGIN to be the index of the first character.
◦ Strict Singularity Check—Controls the matrix inversion algorithm used by PTC Mathcad. When a singular or ill-conditioned matrix is inverted, it can return a result that is not a true inverse. That is, M·M-1 may not be equal to the identity matrix. Select this option to check whether the input matrix or the inverted matrix is as follows:
▪ Singular—The matrix determinant is equal to zero or its rank is incomplete (the rows and columns of the matrix are not linearly independent).
▪ Ill-conditioned—The matrix has a high condition number, which is the ratio of the largest magnitude eigenvalue to the smallest. Use the cond2 function for calculating the condition number of your matrix.
When PTC Mathcad detects such a matrix, an error message appears.
This option uses a more rigorous but slower matrix inversion algorithm.
◦ Multithreading—Controls the number of calculations that can run in parallel. When this option is active, PTC Mathcad can simultaneously perform multiple independent calculations. This may speed up the calculation of some worksheets that contain a number of independent calculations, by better utilizing multi-processor systems.
Multithreading is a per user setting. It is disabled by default, but users can click the button to enable/disable this functionality. The state of multithreading is preserved and affects all open worksheets, newly opened worksheets, or worksheets that are open after closing and restarting PTC Mathcad.
◦ Units/Constants in Symbolics—Controls the automatic labeling of certain variables as built-in units and constants in symbolics.
