Programming in Turbo Pascal

Speaking about Pascal, it is clear that the Delphi Programming Environment is the most significant nowadays. Indeed, programs in Turbo Pascal tend to become outdated on Windows systems. Sad remark: Turbo Pascal executables nevertheless are significantly smaller & faster than their 32-bits counterparts. As an inheritage from my Turbo Pascal period, only the graphical results have been retained, for three problems. And, meanwhile, all TP code has been converted to Borland Delphi. As far as Delphi is concerned, a sad remark is in place, though: Turbo Pascal executables were significantly smaller & faster than their 32-bits Delphi counterparts. And the higher the Delphi version, the more inefficient it has become.

Numerical Analysis

General Units

Every TP program consists of a specific part and more general parts, the so called Turbo Pascal Units (TPU's).
The following is a list of the more general units in the TP ZIP archive. The Mouse Library was developed originally for the purpose of mimicking (muistest.pas) the excellent X-Windows drawing program called 'xfig', but I did'nt finish this part of the job.

The performance of Skew Upwinding has been somewhat disappointing, despite of my theoretical and (zoek3uit.pas) programming effort spent on the subject.
Attempts to generalize the idea to multiple dimensions (say 3 + 1 = space plus time) seem to be even more discouraging. There exist 58 tetrahedra which share their corner points with those of one cube in 3-D. (This strategy is quite different from the one which was outlined in previous work and which should be characterized now as rather incomplete). In 4-D there exist 3008 such pentahedra, however, as has been found by running another little (combine4.pas) program. Imagine what calculation time would be involved with just one of these space-time elements!

The Labrujère Problem

The following issues are dealed with:
  1. Ideal Flow velocity distribution around a circular cylinder
    A Least Squares Finite Element Method has been implemented for this purpose.
  2. Potential lines and Streamlines calculated from the velocity field
    Also calculated with a Least Squares Finite Element Method.
  3. Potential and Streamline function calculated conventionally
    by employing a common Finite Element Method.
  4. Velocity distribution derived from both the Potential and the Streamline function
    using "numerical differentiation" (not really).
ZIP archive contents: These programs are associated with chapter 7 (Dutch) in my book, known (to me at last) as Labrujère's Problem.
Check out here for more relevant parts. The results are displayed graphically.

Corroding Reinforced Concrete

This program calculates the distribution of the electrical potential, and the electric field, in a piece of re-enforced concrete.
A standard 2-D finite element method has been implemented for this purpose.

ZIP archive contents:

The results are displayed graphically.

Intermediate Heat eXchanger

Transport Phenomena in a Heat Exchanger are calculated and theory is checked against temperature measurements.
As follows:
  1. Ideal Flow velocity distribution at the inflow region
  2. Potential lines and Streamlines at the inflow region
  3. Pure Convection at the inflow region (along with streamlines)
  4. Primary and Secondary Temperatures in the tube bundle
A Least Squares Finite Element Method has been implemented for this purpose.
Straight and Skew Upwind Finite Element Difference (SUFED) schemes are used for convection.
Direct as well as iterative methods are employed for solving the system of linear equations.

ZIP archive contents:

Statistics

Here are some of my Turbo Pascal programs I developed while studying a little bit of Statistics
(though I'm particulary bad in this area): (Note: many of these programs will not work anymore anyway, without the Borland BGI stuff, which must then be placed in the C:\TP\BGI directory.)

The first two programs are characterized by the use of recursion.

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