It is possible to delete points for which given condition is true, (with interpolation of y and σ): X = x + n * (x-x) / (M-1), Y = y, S = s This enables equilibrating the step of data X equal arg, or, if there is no such point, the linear interpolation
The special index(arg) function returns the index of point that has This makes possible to swap the axes: X=y, Y=x Transformations separated by commas ( ,) form a sequance of transformations.ĭuring the sequance, the vectors x, y, s and a that contain If the index is less than 0 or larger than M-1, 0 is returned. For X, Y, S, A the index is rounded to integer.Or the last point, respectively, is returned. If the index is less than 0 or larger than M-1, the value for the first If the index is not integer (it is compared using ε to the rounded value):įor example, y is equal to (y+)/2. Indices, like all other values, are computed in the real number domain. The sorting is performed after each transformation.Ĭhanging the x coordinate may change the order Points are kept sorted according to their x coordinate. Points can be created or deleted by changing the value of M.įor example, the following commands: M=500 x=n/100 y=sin(x)Ĭreate 500 points and generate a sinusoid. It is possible to select active range of data: A = x > 40 and x `) Negative y values can be zeroed: Y = max2(y, 0)Īll standard deviations can be set to 1: S = 1 real numbers in normal or scientific format (e.g.The value of undefined points, like y and Y, So effectively it adds the sum of all previous points. The second one adds the value of the previous point after transformation, The first one adds to each point the value of the previous point. For example, the two commands: Y = y + yĭiffer. So while Y and y have always the same value, Operations are applied sequentially from the first point to the last one, Is assigned y value of the n-th point from the end.īefore the transformation a new array of points is created as a copy of the n stands for the index of currently transformed point,Į.g., Y=y means that n-th point ( n=0, 1.upper case X, Y, S, A stand for the same properties.lower case letters x, y, s, a represent properties of data.The right hand side is a mathematical expression that can have special S, A, possibly with the index in brackets. On the left side of the equality sign you can have one of symbols X, Y, Y = -y changes the sign of the y coordinate for all points.Y=1.2 assigns the y coordinate of the 4th point (0 is first),.It is possible to either change a single point or applyĪ transformation to all points. These properties can be changed using symbols X, Y, S and A, Standard deviation of y and active/inactive flag. Data Point TransformationsĮvery data point has four properties: x coordinate, y coordinate,
Should be assumed, but it is her responsibility to pick something. It is often the case that user is not sure what standard deviation You can always change the standard deviation, e.g. as a square root of the value is commonĪnd has theoretical ground when y is the number of independent events. Or to 1, depending on the :option:`default_sigma` option. Otherwise, it is set either to max( y 1/2, 1) :ref:`read from file ` together with the x and yĬoordinates. We can also think about weights of points - every point has a weightĪssigned, that is equal w_i=1/\sigma_i^2. (optimization), look at the weighted sum of squared residuals formula To see how the y's standard deviation, σ, influences fitting When fitting data, we assume that only the y coordinate is subject to Points are loaded from files using the command: dataslot `: A = boolean-conditionĬan be used to change the state of points.ĭata points can be activated and disactivated with mouse If it just works for your files, you may go
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