Hello everyone,
I'm experiencing an issue regarding surface roughness calculation and I could use some help in troubleshooting.
Here's what I've done so far:
This leads me to a couple of doubts:
a) Are the coordinate data provided by the Wyko vision software in ASCII format for Ra and Rq calculations the actual raw data, or has it been processed in some way by the software before the calculations are performed?
I'd appreciate any guidance on this issue, specifically on understanding the data processing done by Wyko software and how I can ensure my Matlab script is accurately calculating the roughness parameters.
I've also attached the ASCII file below for reference.
Thank you in advance for your help!
To calculate roughness from a Wyko Vision ASCII file using MATLAB, you can use the following steps:
1. Load the data from the Wyko Vision ASCII file using the `importdata` function in MATLAB. This function reads data from text files and returns a struct containing the data.
```matlab
data = importdata('wyko_ascii_file.asc');
```
2. Extract the x, y, and z data from the struct and store them in separate arrays.
```matlab
x = data.data(:, 1);
y = data.data(:, 2);
z = data.data(:, 3);
```
3. Calculate the mean height of the surface using the `mean` function in MATLAB.
```matlab
mean_height = mean(z);
```
4. Subtract the mean height from the z data to obtain the deviation from the mean.
```matlab
deviation = z - mean_height;
```
5. Calculate the root-mean-square (RMS) roughness using the `rms` function in MATLAB.
```matlab
rms_roughness = rms(deviation);
```
6. Optionally, you can also calculate the arithmetic average roughness (Ra) and the maximum height (Rmax) using the `mean` and `max` functions in MATLAB.
```matlab
Ra = mean(abs(deviation));
Rmax = max(abs(deviation));
```
Note that the above code assumes that the Wyko Vision ASCII file contains three columns of data representing x, y, and z coordinates. If the data is organized differently, you may need to adjust the code accordingly.
Also note that the roughness calculation performed here is a basic calculation and does not take into account other factors such as filtering or wavelength weighting. If you require a more sophisticated roughness calculation, you may need to use additional MATLAB functions or third-party software.
Hope it helps
Credit: mostly AI Tools
I have tried the above code but my answer dosent match with value shown in software.
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