# Questions tagged [interpolation]

Anything related to function interpolation, i.e. the mathematical techniques for estimating the (unknown) value of a function in a point on the basis of a set of known values in other (usually nearby) points. For interpolation of strings, see [tag:string-interpolation].

3,473 questions
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### Is there much faster way to substitute 'scipy.ndimage.interpolation.zoom'?

I'm trying to resize my 3D images (voxels with shape '1, x, y, z') to fixed-size images, say ('1, 100, 100, 100'). I have tried the followings, zoom(input_image, scale, order=1) skimage....
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### Interpolation on n-dimensional grid impossible through scipy.interpolate.griddata

I have an array of observations called values which comes from a function defined the following way: values = np.array([oscillatory(i) for i in range(points.shape[0])]) values has shape (65,1), ...
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### Catmull-rom and Akima not including part of curve?

My original image is a fragmented curve which I've skeletonized to reduce the number of points. I'd like to join the curve together using a method which might also work for images that are straight ...
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### Performing an ordinary kriging on MATLAB

I'm trying to use the function from the following link to perform an ordinary kriging on my data in MATLAB! https://www.mathworks.com/matlabcentral/fileexchange/29025-ordinary-kriging It seems simple ...
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### Interpolating (kriging?) Grid Data in MATLAB

I have Lat, Lon, and NO2 data that are gridded. I'm trying to select a few points from this data and interpolated out some data/a plot, comparing how this interpolated data/plot improves as I ...
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### How can I create spark udf for interpolation of float to INT and how can I write better logic than I have done

Below is my Spark Dataframe I want to do interpolation and write a Spark UDF for this I am not sure how can I write better logic and create a UDF from above This is for converting Position_float and ...
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### Interpolation with forloop in query

I'm writing a query in a forloop and I don't know where I'm mistaking. in a nutshell, what I need is to do a for loop and in the WHERE statement put the content of a dict. Can someone help me? ...
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### How to make a spline interpolation with a defined slope on only one end?

I have some data that I would like to interpolate using a cubic spline in Matlab. My data is monotonically increasing, but the default spline result has a large downward curve that falls below zero. ...
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### How to interpolate a variable into a regex-pattern in the regex part of a substitution?

What do I have to change here to make it work? my \$str ="start middle end"; my \$regex = / start ( .+ ) end /; \$str.=subst( / <\$regex> /, { \$0 } ); # dies: Use of Nil in string context say "[...
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### Matlab Use function with structure parameter to interpolate

In MATLAB, I want to interpolate on a set of data using a function with the parameter input as a structure. However, I am receiving an error. I have a structure: fruit.apples = [3 4 2 3 4] fruit....
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### Given a 10th percentile event in one variable, give me the corresponding 90th percentile value for a correlated variable

Let's assume I have a multivariate random normal generating function with some means, and covariance matrix. I can use numpy to generate data using: import numpy as np import pandas as pd means = [...
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### Interpolating a data series of longitude and latitude coordinates - Error in input data

I would like to perform a interpolation based on a set of Longitude and Latitude values. I tried this with the library SciPy.interpolate. The code shown below also works without problems on simple ...
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### How to interpolate data to a different sampling frequency?

I have a pandas dataframe with a sampling period of 18 seconds I want to do linear interpolation and have a value every 9 seconds. So the dataframe looks like this timestamp,c0 2016-01-01T00:00:12....
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### 3D interpolation of display RGB using display XYZ and RGB

I am working on a display and I want to interpolate RGB values from XYZ. I used devices to measure XYZ value corresponding to the RGB (9x9x9) values. Now, I have XYZ of my image and I want to convert ...
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### How to “stretch” my dataframe and interpolate in between existing values

I'm stuck with a simple DataFrame.reindex().interpolate() problem because the dataframes I am using don't have a datetime index. I have DataFrame1: t that looks like this: In[1]: import pandas as pd ...
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### Interpolating matrices with 2 variables and 1 dependent value

I'm analyzing an induction motor, varying the frequency and absolute value of the stator current. Since the FEM-Tool only works with a current input, I need to vary the current over the frequency to ...
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### How to fill in the empty space in between images for volumetric imaging/ 3D reconstruction in matlab

I am trying to create a 3D model of packed spherical beads with image slices. These images are of spherical beads with varying diameters, taken 0.0015 apart. The cube is 2.154x2.154x2.154. I was able ...
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### Interpolate two-dimensional numpy array with respect to the periodicity of the values

I have points (x, y) with a value (z) which is periodic in pi, i.e. zero is the same as pi. The points are very coarse so I need to interpolate them. I tried interpolating the values with griddata() ...
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### I need to smoothly interpolate an object with position x, y, z to multiple 3D points in a row

I have an ArrayList of 3D points as such: ArrayList<float[]> These points are placed in a ring around 0,0,0. Right now I have my ring generation code just add 24 3D points to this array (360 ...
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### Conditional interpolation with subject

I have an Subject which provides me with number. In my template, I would like to render this number in braces, if it is higher than 0. Theoretically something like this (this does not work though): ...
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### Does Angular handle interpolation and one way binding the same way?

I am currently creating an application that frequently changes the text and images on a page. Chrome consumes almost the whole cpu after a few hours of running. Please note that it is not an option to ...
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### jQuery/CSS interpolation doesn't add anything to the element

I am adding a width to an element using jQuery, but when i use a variable, it doesn't add anything. This works perfectly when i replace the js variable with a number, but doesn't work at all when i ...
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### Interpolation Errors, plot function does not generate proper lines when running

I am trying to get a graph made for my interpolation program (basically it takes a test function and creates lines utilizing an interpolation method) clear all; close all; clc; x1= [-1 0.75 -0.5 -0....
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### Color interpolation with a set of 2D points

I am trying to modelize a physical problem of photoelasticity on a surface. I succeed to get an array of X,Y - coordinates of the surface and for each points I have a corresponding color in a RGB ...
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### Linear Interpolation with krige-Function in R

I'm doing a regression kriging in R and have already done the ordinary kriging with the residuals which worked absolutely fine. Now I want to do the linear regression with three prediction variables ...
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### Python | How interpolate two measurements such that the x-values are the same

I have two measurements consisting of x and y value pairs. I want to calculate the difference between these two series. The problem is that I cannot simply calculate the difference between these two ...
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### How to calculate “in between results” based upon given reference list with additional serial number identification?

For (almost) each technical visit there is a record: SERVICE DATE / MACHINE #SN / HOURS OF OPERATION in Table A (all machines in the same list). All installed spare parts are recorded with DATE ...
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### Intrepolating between two data frames

i have two data frames a= x y 10 10 47 9 58 8 68 7 75 6 80 5 b= x y 45 10 55 9 66 8 69 7 79 6 82 5 I want to interpolate between them and generate new data frame with N sampling ...
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### How do I interpolate values for blank rows column-wise within the same row name, and then copy the interpolated data to the original DataFrame?

I have a spreadsheet that gives the statistics of the 2019 World Happiness Report which will be later used in a visualization and linear regression problem (it is a group project and my part is ...
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### How to apply na.approx to a row in a matrix?

I am trying to make an interpolation for all the rows in a dataframe. I am using apply(data_final,2,na.approx). This make the interpolation for the values but some are out of range. If I use na....
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### Cubic extrapolation equation in fmincg.m

Can you tell me these equations come from where in MATLAB fmincg.m? A = 6*(f2-f3)/z3+3*(d2+d3); % cubic fit B = 3*(f3-f2)-z3*(d3+2*d2); z2 = (sqrt(B*B-A*d2*z3*z3)-B)/A; % numerical ...
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### Angular - Cannot concatenate values in HTML page

In our Angular project, we use interpolation as shown below, but we also need to use this interpolated value in the [state] property. But we haev not managed so far. Any idea? If we set id values as ...
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### Trouble formatting x and y data in gekko's bspline function

I am trying to perform 2D interpolation in GEKKO, and have the x,y, and z data. However, when I input them into the bspline function, I get the error "x_data and y_data must be strictly increasing". ...
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### Interp2 function returns faulty interpolated matrix

I have a question concerning the interpolation 2 function. I am trying to interpolate some data matrix which is in respect to a cartesian grid. I have to interpolate the data to a polar grid (not with ...
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### Find (x,y) subpixel coordinates of a maximum using discrete quadratic interpolation

I have to find the subpixel (x,y) coordinates of the maximum value given a set of discrete points.Im ny case, I run cv::matchTemplate function that slides a model window along an image and returns a ...
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### Invalid “times” argument in R package “fields”.. Fail to solve it

I am trying to interpolate some NAs of an environmental dataset. The error that is shown to me is: "Error in rep(0, n1 * n2) : invalid 'times' argument In addition: Warning message: In n1 * n2 : ...
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### How to generate a 3D array of data based on a 1D array of data and three 1D arrays of spatial coordinates

I have 3D scattered data that I need to interpolate. My chosen interpolation method requires inputs of (x,y,z,v) where: (x,y,z) spatial coordinates of original grid (1D or 3D arrays) (v) values ...
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### Using interpolation outside function definition in solution using Runge-Kutta 4th order

I have written MATLAB code to solve the following systems of differential equations. with where and z2 = x2 + (1+a)x1 a = 2; k = 1+a; b = 3; ca = 5; cb = 2; theta1t = 0:.1:10; theta1 = ca*...
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### Interpolat​ion/Extra​p​olation 3D Marker Coordinates

I have x,y,z coordinates for 3 markers (Thigh.1, Thigh.2 & Thigh.3) fixed on a rigid pad tracking the motion of the thigh during running. Trials are generally ~100 frames long. For some trials the ...
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### interpolate a closed surface in python

I have a set of 3-dimensional points that are scattered on the surface of a closed object, which has roughly the shape of an ellipsoid. Now I need to find all points on a 3-dimensional cartesian grid ...
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### How do I interpolate between file creation dates?

I have a GoPro Hero 4. The watch chip seems to be broken. Each time the battery becomes completely empty, the clock sets itself to approx. 01.01.2015 00:00:00. If I see that, I set the time again ...
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### plot image with interpolation in Python Bokeh like matplotlib?

Is there any way to plot 2D array as an image using Bokeh with interpolation like in Matplotlib? I am able to plot using an example: https://bokeh.pydata.org/en/latest/docs/gallery/image.html However, ...
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### Interpolate bounded pixels in python

I have a matrix of values between 0 and 1. The matrix consists of blocks of values which are the same, but with different widths. The image below is a visual picture of this matrix. I would like to ...
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### Peak correlation and interpolation between two data sets

I have a bunch of power data in the frequency domain that I wish to parameterize. I want to interpolate between two data sets and retain the harmonic relationships. Is there a Python package out there ...
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### Treat the missing values (conditional Imputation ) Pandas

I have a block in the processing of missing data i have this df index a b c del 2018-06-25 12:51:00 NaN NaN NaN 1 2018-06-25 12:52:00 NaN ...
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### interpolate sass values between breakpoints

I have backend data that is inserting a class into an html tag to force an image's ratio via sass/css with the padding-top trick. If you set an image's height and width to zero and only set the ...
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### Tagged template literals confusion [closed]

I'm at the point in my learning curve of JavaScript where I need to learn some more complex things to get better, and I'm starting with tagged template literals but I can't seem to wrap my head around ...
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### Storing data before passing it to interpolation routine

I'll begin by apologizing, because I'm entirely new to python(Fortran guy here), and have been learning on the fly. As a result, there are probably some pretty glaring holes in my knowledge that may ...