# Wireline
**by [Matt Hall](https://github.com/kwinkunks)**
You have a 'log', a series of bulk density measurements from a borehole. There is a measurement every 0.1524 m, starting at the top of the borehole. The measurements have units of kg/m^{3} and look like this:
2193.5,2234.3,2270.2,2764.4,2781.8,2805.7,2794.3,2784.0,2057.9,2006.8,2007.1,2033.2
The log contains a number of geological 'beds' which have a very specific definition: neighbouring pairs of samples that differ by more than 100 kg/m^{3} constitute a bed boundary. These are bed boundaries. Any section of the log between two bed boundaries is a bed. If the boundaries are 5 samples apart, assume the bed is 5 × 0.1524 = 0.7620 m thick.
Answer the following questions about your data.
1. How many samples are in your dataset?
2. Calculate the mean μ and standard deviation σ of the data. How many samples are greater than (μ + σ)?
3. How many beds are there? Include the first and last beds (those at the very top and bottom of the log).
4. How many beds are thicker than 10 m?
## Example
For the short example data above, the questions would be answered as follows:
1. There are **12** samples in the dataset.
2. μ is 2394.4 and σ is 340.74, so **5** samples are greater than (μ + σ).
3. There are **3** beds in the data, with densities of about 2200, 2800, and 2000 kg/m^{3} respectively.
4. The bed thicknesses are 0.4572, 0.7620, and 0.6096 m respectively, so **0** of these beds are thicker than 10 m.
## A quick reminder how this works
This document is formatted in [Markdown](https://daringfireball.net/projects/markdown/).
You can retrieve your data, which is always a string, by choosing a **``** (also a string). This ensures that you have different data from other people, so be creative.
```
url = 'https://kata.geosci.ai/challenge/wireline'
params = {
'key': # Replace with your own string.
}
r = requests.get(url, params)
r.text
```
To answer question 1, change the `params`:
```
params = {
'key': , # Use the same key you used to get your input.
'question': 1,
'answer': 1234 # Your answer; can be a float, int, list or array;
# the challenge description will tell you which.
}
```
To get a hint for a question, provide the question number but no answer:
```
params = {
'question': 1,
}
```
[Complete instructions at kata.geosci.ai](https://kata.geosci.ai/challenge)
[An example notebook to get you started](https://gist.github.com/kwinkunks/50f11dac6ab7ff8c3e6c7b34536501a2)
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