linear-interpolation

I am trying to use Oracle 11g (11.1 in dev, 11.2 in production) for numeric analysis, specifically linear interpolation on a table which has three columns of interest: a timestamp, a deviceid, and value. The value columns holds data from the device (with id deviceid), taken at the time given in the timestamp. For example, this is bogus data, but it gives the idea: time | deviceid | value ----------------|------------|----------- 01:00:00.000 | 001 | 1.000 01:00:01.000 | 001 | 1.030 01:00:02.000 | 001 | 1.063 01:00:00.050 | 002 | 553.10 01:00:01.355 | 002 | 552.30 01:00:02.155 | 002 | 552.43

This is a continuation of a question that I had originally posted at http://r.789695.n4.nabble.com/subset-between-data-table-list-and-single-data-table-object-tp4673202.html . Matthew had suggested that I post my question here so I am doing that now. This is my input below: library(data.table) library(pracma) # for the interp1 function tempbigdata1 <- data.table(c(14.80, 14.81, 14.82), c(7900, 7920, 7930), c("02437100", "02437100", "02437100")) tempbigdata2 <- data.table(c(9.98, 9.99, 10.00), c(816, 819, 821), c("02446500", "02446500", "02446500")) tempbigdata3 <- data.table(c(75.65, 75.66, 75

I have three 3D points like p1(x1,y1,z1) , p2(x2,y2,z2) , p3(x3,y3,z3) . I have another point, but I know only x , y value of that point like p4(x4,y4,Z) , in which Z is the value I like to compute. I am sure p4(x4,y4) point is inside a triangle formed by p1(x1,y1) , p2(x2,y2) , p3(x3,y3) by checking with delaunay triangulation approach. How can I compute Z value of point p4 ? I like to implement it in C programming. Actually I am trying to implement griddata in MATLAB. Thanks You can express P4 coordinates in the P1P2P3 vector basis. x4 = x1 + A * (x2 - x1) + B * (x3 - x1) y4 = y1 + A * (y2 -

For a LPC922 microcontroller (with SDCC) I want to create a lookup table with linear interpolation. Lets assume I got x and y values like x=300 y=10,0201 x=700 y=89,542 x=800 y=126,452 x=900 y=171,453 x=1500 y=225,123 How can the code for a lookup table with linear interpolation look like, so I get for example for x=850 the right value for y ((171,453+126,452)/2)? typedef struct { double x; double y; } coord_t; coord_t c[5] = { {300, 10.02}, {700, 89.542}, {800, 126.452}, {900, 171.453}, {1500,225.123} }; double interp( coord_t* c, double x, int n ) { int i; for( i = 0; i < n-1; i++ ) { if ( c

Below is a cubic interpolation function: public float Smooth(float start, float end, float amount) { // Clamp to 0-1; amount = (amount > 1f) ? 1f : amount; amount = (amount < 0f) ? 0f : amount; // Cubicly adjust the amount value. amount = (amount * amount) * (3f - (2f * amount)); return (start + ((end - start) * amount)); } This function will cubically interpolate between the start and end value given an amount between 0.0f - 1.0f. If you were to plot this curve, you'd end up with something like this: Expired Imageshack image removed The cubic function here is: amount = (amount * amount) * (3f

Using MATLAB, I would like to linearly interpolate between every point in an array. Using interpolate will do it in a non-linear fashion. What I want to do is similar to producing low-pass filter coefficients. I have come up with a solution, but I would like to avoid using for loops: a=[0 0 1 0 0]; %Input matrix N=5; %Number of points to be added b=[]; for i=1:length(a)-1 b=[b linspace(a(i),a(i+1),N)]; end Is it possible to do this without a loop? You can create a linear spline with the points in a as control points. After that you can specify as many points as you want from a beginning