This page allows performing constrained linear regressions (linear regressions with a fixed point, constrained linear least squares fittings). For the relation between two variables, it finds the linear function that best fits a given set of data points and that fulfills an equality constraint consisting in that the line has to pass through a fixed point.
• Copy & Paste: You can specify the equality constraint (fixed point) and then copy and paste data directly from a spreadsheet or a tabulated data file in the box below. Any character that cannot be part of a number -space, comma, tabulation...- is considered a column separator. By default commas are considered column separators; in the case you are using them as decimal separators check the option below. The exponent can be indicated by preceding it by the character E or e, as you can see in the example. Data must consist of two columns, x and y, to get the constrained linear regression y=ax+b.
• Insert manually & See details: If you prefer you can insert all the points manually, for which you first have to specify the number of data points. You also can see details of the calculation -as the calculated value of y and the error at each point- in this area.