# 2.8. Creating Slides¶

We can mark a notebook and then create slides from that notebook. For example, here is the generate slides from the markdown source file. Let explain how to do it by the following example. It’s a markdown file with marks to generate slides.

```# Data Manipulation

## Getting Started

To start, we can use `arange` to create a row vector `x`
containing the first 12 integers starting with 0,
though they are created as floats by default.

A tensor represents a (possibly multi-dimensional) array of numerical values. We can access a tensor's *shape*.

```{.python .input}
import numpy as np

x = np.arange(12)
x
```

Many more operations can be applied elementwise,
including unary operators like exponentiation.

```{.python .input}
np.exp(x)
```

Even when shapes differ, we can still perform elementwise operations
by invoking the *broadcasting mechanism*.

```{.python .input}
a = np.arange(3).reshape(3, 1)
b = np.arange(2).reshape(1, 2)
a, b
```
```

The above code block will generate 2 slides. The first slide contains the following contents:

```# Data Manipulation

A tensor represents a (possibly multi-dimensional) array of numerical values. We can access a tensor's *shape*.

```{.python .input}
import numpy as np

x = np.arange(12)
x
```
```

You can see that we automatically copied the level-1 heading and the code block. In addition, we copied the text between `and`, while dropped all others.

The second slide contains the following:

```Many operations can be applied elementwise,
e.g. `exp`

```{.python .input}
np.exp(x)
```

Even when shapes differ, we can still perform elementwise operations

```{.python .input}
a = np.arange(3).reshape(3, 1)
b = np.arange(2).reshape(1, 2)
a, b
```
```

First you can see is that all text between these three paris (`,`), (`,`), and (```) are kept. Here``[`means starting a new slide, while`(`means continuing the current slide. (Level-1 heading will start a new slide, so we used`(`in the previous block). In addition,`~~` means the text will only appear in slides, why not in the normal notebooks, htmls or pdfs.

Second, we didn’t start a new slide before the last code block, i.e. there is no level-1 heading and no (`,`) pair, so the last two code blocks are merged into the same slide.