TRIANGLE_ANALYZE
Compute Properties of a Triangle

TRIANGLE_ANALYZE is a FORTRAN90 program which reads a triangle defined in a file, and uses the TRIANGLE_PROPERTIES library to compute angles, area, centroid, circumcircle, edge lengths, incircle, orientation, orthocenter, and quality.

Usage:

triangle_analyze filename

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

TRIANGLE_ANALYZE is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

GEOMETRY, a FORTRAN90 library which performs geometric calculations in 2, 3 and N dimensional space.

TRIANGLE_INTERPOLATE, a FORTRAN90 library which shows how vertex data can be interpolated at any point in the interior of a triangle.

TRIANGLE_PROPERTIES, a FORTRAN90 program which computes properties of triangles.

TRIANGLES, a dataset directory which contains examples of triangles;

Source Code:

• triangle_analyze.f90, the source code.

Examples and Tests:

• tex1.txt, example 1.
• tex1_properties.txt, the output file.
• tex2.txt, example 2.
• tex2_properties.txt, the output file.
• tex3.txt, example 3.
• tex3_properties.txt, the output file.
• tex4.txt, example 4.
• tex4_properties.txt, the output file.
• tex5.txt, example 5.
• tex5_properties.txt, the output file.
• tex6.txt, example 6.
• tex6_properties.txt, the output file.
• tex7.txt, example 7.
• tex7_properties.txt, the output file.
• tex8.txt, example 8.
• tex8_properties.txt, the output file.
• triangle_cap.txt, example of a "cap" triangle.
• triangle_cap_properties.txt, the output file.
• triangle_equilateral.txt, example of an equilateral triangle.
• triangle_equilateral_properties.txt, the output file.
• triangle_needle.txt, example of a "needle" triangle.
• triangle_needle_properties.txt, the output file.
• triangle_ref.txt, example of a reference triangle.
• triangle_ref_properties.txt, the output file.
• triangle_right.txt, example of a right triangle.
• triangle_right_properties.txt, the output file.

List of Routines:

• MAIN is the main program for TRIANGLE_ANALYZE.
• CH_CAP capitalizes a single character.
• CH_EQI is a case insensitive comparison of two characters for equality.
• CH_TO_DIGIT returns the value of a base 10 digit.
• FILE_COLUMN_COUNT counts the number of columns in the first line of a file.
• FILE_ROW_COUNT counts the number of row records in a file.
• GET_UNIT returns a free FORTRAN unit number.
• R8MAT_DATA_READ reads data from an R8MAT file.
• R8MAT_HEADER_READ reads the header from an R8MAT file.
• S_TO_R8 reads an R8 from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_WORD_COUNT counts the number of "words" in a string.

You can go up one level to the FORTRAN90 source codes.