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Category Archives: Charts
Iterative solvers and arrays
A recent thread at Eng-Tips was looking for a solution to the problem described below: The solutions to this problem described below can be downloaded from: ItSolve.zip and xlScipy3.zip The ItSolve.xlsb spreadsheet contains a user defined function (UDF) to solve iterative … Continue reading
Arcs and arc-splines
I have added two user defined functions (UDFs) to the IP2 spreadsheet to generate coordinates for a single arc, or a series of arcs connected (if necessary) by straight lines. The new version may be downloaded from: IP2.zip As an example … Continue reading
Plotting Charts With Gaps …
“How do you get VB6 to initialize doubles with +infinity, -infinity and NaN”… and various sorts of Not a Number. Back in 2012 (When is an xy chart not an xy chart) I concluded that it was not possible to … Continue reading
Posted in Arrays, Charts, Charts, Excel, UDFs, VBA
Tagged Chart, NaN, plot blank, XY chart with gaps
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Using Matplotlib from Excel with xlwings – update
In February 2016 I posted a spreadsheet with examples of linking to the Python Matplotlib library with xlwings. Since then updates to xlwings required some changes to the python code, specifically plot.show has been replaced with pictures.add. The spreadsheet has … Continue reading
Posted in Charts, Charts, Excel, Link to Python, Newton, NumPy and SciPy, VBA
Tagged Excel, MatPlotlib, Python, update, VBA, xlMatPlot, xlwings, xlwScipy
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More on trend line equations on line charts
In the previous post we saw that if a trend line equation is added to a line chart it will return the wrong coefficients if the x values are not a continuous sequence of integers, starting at 1 (click on … Continue reading
Posted in Charts, Excel, Maths, Newton
Tagged chart trend line, Charts, Excel, line chart, XY chart
1 Comment
Displaying trend line equations on line charts
This post is prompted by a recent comment at Using LINEST for non-linear curve fitting which found that the trend line formula displayed on a chart was totally different from that found using the Linest function. The problem was caused by using a … Continue reading
Posted in Charts, Charts, Excel, Maths
Tagged Chart, Excel, Show trend line equation, Trend line
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A mystery curve links to Jupyter
Reviewing some of my less visited links recently, I was intrigued by a post at The Math Less Travelled: The previous post at the site provides more details of the source of the curve, and some links to an interactive … Continue reading
Posted in Charts, Charts, Excel, Maths, Newton
Tagged curve generator, Excel, Jupyter, Maths, parametric curve, Python, Scatter chart
2 Comments
