# Questions tagged [extrapolation]

For question on extrapolation, the process of estimating, beyond the original observation interval.

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### Computing derivative as accurately as possible by finite difference formula

The central difference formula is $D_h(x)=\frac{f(x+h)-f(x-h)}{2h}$. In the form $(x,f(x))$ am given the data points $(0.40, 2.3987), (0.44, 2.4182), (0.48, 2.4377), (0.52, 2.4571), (0.56, 2.4764)$. ...
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### Richardson Extrapolation on forward differencing formula

After deriving this with forward differencing formula & Taylor series: $$D_1 f = f'(x_{i}) = \frac{f(x_{i+1}) - f(x_{i})}{h} - \frac{f''(x_{i})h}{2!}$$ which could perhaps also be written as: ...
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### Nowcasting, what is it?

I stumbled upon this word in the context of corona virus forecasting. As far as I understand it is some kind of extrapolation method that is also used in economics and meteorolgy, but am struggling ...
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### How to do a weighted extrapolation using a Burg (or similar)?

I had extrapolated data using the Burg Method (octave arburg) but in the period with no existing data the extrapolated value kept on asymptotically tending to an arbitrary value even when the data ...
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### Gaussian normal distribution extrapolation methods

Some graphs of COVID-19 If I assume that active cases of COVID-19 fits to Gaussian normal distribution curve, how I can extrapolate current numerical data to draw whole curve? See the linked image ...
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### Interpolating values using a fitted function

I have data for $x,y$ where $y=[0,0,0.016,0.65,0.97,0.99,1]$ and $x=[1,2,3,4,5,6,7]$. For this data I fitted a sigmoid type function as $f(x)=a/(1+exp(-b*x)+c)$. I fitted this using matlab cftool, and ...
26 views

### How to extrapolate the data?

The question demands me to find "rupture lifetime" for 300MPa load at a temperature of 649$^{\circ}$ C.How do I solve it?All that I know is to apply interpolation and extrapolation which I ...
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### Fitting a surface to a set of 3d points

I am attempting to fit a surface to a set of 3d points. These points never overlap on the x,z plane, and do fit into a grid, but may be sparse. Our current implementation just uses bilinear ...
Suppose that the interval of integration $[a,b]$ is divided into equal subintervals of length $h$ each such that $r = \frac{b-a}{h}$ is even. Denote by $R_1$ the result of applying the composite ...