# Monthly Archives: June 2020

## Draw many circles that intersect two points in C#

As I mentioned in my earlier post Connect two points with elliptical arcs in C#, an infinite number of circles (or ellipses) can pass through two points. This example draws some of them to produce an interesting pattern. This example … Continue reading

Posted in algorithms, drawing, graphics, mathematics | | 1 Comment

## Connect two points with elliptical arcs in C#

As I mentioned in my earlier post Connect two points with arcs of midpoint circles in C#, two points alone cannot uniquely define a circle. An infinite number of circles (or ellipses) can pass through two points and therefore they … Continue reading

Posted in drawing, graphics, mathematics | | 1 Comment

## Connect two points with arcs of midpoint circles in C#

Two points alone cannot uniquely define a circle because an infinite number of circles can pass through two points and therefore they can be connected by an infinite number of arcs. If you add extra information, however, two points can … Continue reading

Posted in drawing, graphics, mathematics | | 1 Comment

## Improve the program that displays COVID-19 data for US states in C#

This post describes two improvements to the earlier example that displays COVID-19 data for US states. The first change is a basic software engineering improvement. The second displays daily changes in COVID-19 case, hospitalization, and death numbers. Software Engineering Notes … Continue reading

## Use VBA to make a Gantt chart showing work schedules

This example shows how to use VBA (Visual Basic for Applications) in an Excel workbook to draw a Gantt chart showing when employees are scheduled to work. This isn’t C# programming, but you may find it useful. (And I don’t … Continue reading

## Create a Contain FillMode for filling polygons in C#

The example Understand fill modes in C# showed how the Alternate and Winding FillMode values affect the result when you fill a self-intersecting polygon. In many cases, the Alternate FillMode leaves holes in a self-intersecting polygon while the Winding FillMode … Continue reading

Posted in algorithms, drawing, graphics | | 2 Comments

## Find the angle between two vectors in C#

This example shows how you can find the angle between two vectors. The program has three main parts: selecting the points that define the vectors, drawing the vectors, and calculating the angle between them. The last task is the most … Continue reading

Posted in algorithms, geometry, mathematics | | 2 Comments

## Crop scaled images to specific sizes in C#

This example lets you crop scaled images to specific sizes in C#. The post Crop images to specific sizes in C# lets you drag a rectangle of a specified size around on an image to pick the part of the … Continue reading

Posted in drawing, graphics, image processing, tools | | 2 Comments