# View Source Exercises: 1-20

`Mix.install([{:nx, "~> 0.6"}])`

## Introduction

Inspired by the Python notebook 100 Numpy Exercises.

## 1-10

**1. Install Nx in a Livebook. (★☆☆)**

`# Add your solution here.`

## Example solution

**2. Create a 1-D tensor of 10 zeros. (★☆☆)**

`# Add your solution here.`

## Example solution

**3. Find the number of elements in tensor. (★☆☆)**

```
tensor = Nx.tensor([[1, 2, 3], [4, 5, 6]])
# Add your solution here.
```

## Example solution

**4. Find the number of bytes of memory in tensor. (★☆☆)**

```
tensor = Nx.tensor([[1, 2, 3], [4, 5, 6]])
# Add your solution here.
```

## Example solution

**5a. Use Nx.sum/2 to find the sum of all elements of tensor. (★☆☆)**

```
tensor = Nx.tensor([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
# Add your solution here.
```

## Example solution

**5b. Read the documentation for Nx.sum/2 then provide the correct option to sum across the rows. (★☆☆)**

`# Add your solution here.`

## Example solution

*Tip:*You can also hover over a function inside Livebook code cells to display its documentation.

**6. Create a tensor of zeros of size 10 but where the fifth value is 1. (★☆☆)**

`# Add your solution here.`

## Example solution

**7. Create a 3x3 tensor with values ranging from 0 to 8. (★☆☆)**

`# Add your solution here.`

## Example solution

**8. Create a tensor with values ranging from 10 to 49. (★☆☆)**

`# Add your solution here.`

## Example solution 1

## Example solution 2

**9. Reverse tensor (first element becomes last). (★☆☆)**

```
tensor = Nx.tensor([2, 4, 6, 8])
# Add your solution here.
```

## Example solution

**10a. Given an initial tensor, build a "mask" of non-zero elements. That is, build a second tensor with the same shape as the original, but that has a 1 wherever the original has a non-zero element and a 0 elsewhere. (★☆☆)**

```
tensor = Nx.tensor([1, 2, 0, 0, 4, 0])
# Add your solution here.
```

## Example solution

**10b. Use the mask from 10a to replace each 0 from tensor with -1. (★☆☆)**

`# Add your solution here.`

## Example solution

## 11-20

**11. Create a 3x3 identity tensor. (★☆☆)**

`# Add your solution here.`

## Example solution

**12. Create a 3x3x3 tensor with random values. (★☆☆)**

`# Add your solution here.`

## Example solution

**13. Create a random 10x10 tensor then find its minimum and maximum values. (★☆☆)**

`# Add your solution here.`

## Example solution

**14. Create a random 1D tensor of size 30 then find its mean. (★☆☆)**

`# Add your solution here.`

## Example solution

**15. Create a 4x4 tensor with 1 on the border and 0 inside. (★☆☆)**

`# Add your solution here.`

## Example solution

**16. Add a border of 0 around tensor (end result will be a 5x5 tensor). (★☆☆)**

```
tensor = Nx.broadcast(1, {3, 3})
# Add your solution here.
```

## Example solution

**17. Determine the results of the following expressions. (★☆☆)**

```
nan = Nx.Constants.nan()
Nx.multiply(0, nan)
Nx.equal(nan, nan)
Nx.greater(nan, nan)
Nx.subtract(nan, nan)
# Add your solution here.
```

## Example solution

**18. Create a 5x5 tensor with values 1,2,3,4 just below the diagonal. (★☆☆)**

`# Add your solution here.`

## Example solution

**19. Create a 8x8 tensor of 0 and 1 in a checkerboard pattern with 0 as the first element using Nx.tile. (★☆☆)**

`# Add your solution here.`

## Example solution

**20. Produce the same checkerboard pattern from exercise 19, but without using Nx.tile. (★☆☆)**

```
# Add your solution here.
# Hint: try using `Nx.iota` in combination with `Nx.remainder`.
```