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Category Archives: VBA
How to digitise a scanned image
For instance, suppose we had a graph from a technical paper, and we wanted to extract numerical data from the graph lines. One way would be to measure the points by hand and calculate the numbers by scaling from the … Continue reading
The Inverse Quadratic Method 3 – Brent’s Method
The previous post in this series presented iterative methods to solve polynomial equations using direct or inverse quadratic interpolation. These methods have two disadvantages: In some circumstances the function may converge very slowly, or not at all. The name of … Continue reading
Posted in Excel, Maths, UDFs, VBA
Tagged Excel, inverse quadratic, iterative solution, Maths, UDF, VBA
12 Comments
Calling a function as a variable
The functions described in recent posts provide iterative solutions to polynomial equations, but the same method can be used for any equations that can be evaluated numerically and have a single variable. The question then is, how can we call a … Continue reading
Posted in Arrays, Excel, Maths, UDFs, VBA
Tagged application.run, calling a function, equation solver, Excel, iteration, UDF, VBA
6 Comments
The Inverse Quadratic Method – 2
Firstly a clarification from the previous post in this series. The method presented in that post was a direct application of quadratic interpolation, rather than the inverse quadratic method, as implied by the post title. The inverse quadratic method will be … Continue reading
Posted in Excel, Maths, UDFs, VBA
Tagged Excel, quadratic interpolation, Solve polynomial, UDF, VBA
3 Comments
Some VBA maths resources
In the past week I have discovered a couple of sites with open source maths related VBA code that I was previously unaware of, and which deserve to be better known: AlgLib: “ALGLIB is a cross-platform numerical analysis and data processing library. … Continue reading
Newton Excel Bach, not (just) an Excel Blog 