Category Archives: Charts

Daily Download 22: Splines and Curves

Posted on 08/10/2012 by dougaj4

Since it was first published in 2009 my CSpline function has been the most popular download from this site.  CSpline (and various associated functions) is used to fit a series of cubic curves through specified points, allowing interpolation along a smooth … Continue reading →

Posted in AlgLib, Beam Bending, Charts, Charts, Coordinate Geometry, Excel, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , | 7 Comments

Daily Download 14: Curve Fitting 1

Posted on 01/10/2012 by dougaj4

Today’s download topic covers fitting a straight line or curve to scattered data, using the “least squares” method.  Fitting a spline curve to pass exactly through a series of points will be covered in a few days. Use of the … Continue reading →

Posted in AlgLib, Charts, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , | Leave a comment

When is an XY chart not an XY chart …?

Posted on 05/09/2012 by dougaj4

… and whan is a blank cell not a blank cell? To answer the first one, create a simple XY chart, with a single data range of 7 rows, with a blank row in the middle.  This should display as two … Continue reading →

Posted in Arrays, Charts, Charts, Excel, UDFs, VBA | Tagged , , , , , | 18 Comments

Alternative IP and Rotations

Posted on 11/04/2011 by dougaj4

In response to the 3D Intersections and PView Function posts Lori Miller has sent me two very elegant alternative ways of achieving similar results. The first is an on-spreadsheet solution to the intersection of two lines, using the LinEst function: Note … Continue reading →

Posted in Arrays, Charts, Charts, Coordinate Geometry, Excel | Tagged , , , | Leave a comment

PView Function

Posted on 31/03/2011 by dougaj4

As promised in the previous post, here are further details of the PView User Defined Function (UDF), included in the IP2 spreadsheet, which can be downloaded (including full open source code) from IP2.ZIP. The PView UDF works by multiplying the 3D … Continue reading →

Posted in Arrays, Charts, Charts, Coordinate Geometry, Drawing, Excel, Maths, UDFs, VBA | Tagged , , , , , , | 3 Comments