How to display a geometric object from Python code in a Rmarkdown document?

Question

I would like to have a point displayed (like in this tutorial) in my rmarkdown document after knitting.

Reproducible example:

---
title: "Reprex"
output: html_document
---

```{python}
# Import necessary geometric objects from shapely module
from shapely.geometry import Point, LineString, Polygon

# Create Point geometric object(s) with coordinates
point1 = Point(2.2, 4.2)

point1
```

With this code, I only get the following output:

## <shapely.geometry.point.Point object at 0x0000000026EEA0B8>

How can I have the image of the point displayed instead?

Also, I am interested to display it in the viewer/plot pane.

score 1 · Accepted Answer · answered Dec 16 '21 at 20:10

First, not sure if this is crucial, but, following the documentation, we need to add this chunk first:

```{r setup, include=FALSE}
library(knitr)
library(reticulate)
knitr::knit_engines$set(python = reticulate::eng_python)
```

What you want to get is Jupyter-specific functionality. I was able to reproduce it only by converting the point(s) to pure SVG via _repr_svg_() function:

```{python}
from shapely.geometry import Point, LineString, Polygon, MultiPoint

point1 = Point(2.2, 4.2)
point2 = Point(7.2, -25.1)
point3 = Point(9.26, -2.456)
point3D = Point(9.26, -2.456, 0.57)

multipoints = MultiPoint([point1, point2, point3, point3D])
svg = multipoints._repr_svg_()

# or, in your case

svg = point1._repr_svg_()
```

Then displaying it with R chunk:

```{r}
htmltools::HTML(py$svg)
```

I tried doing it on Python-side only (calling r.HTML()), which will only result in textual output.

Note that this will result in the following warning:

sys:1: ShapelyDeprecationWarning: __len__ for multi-part geometries is deprecated and will be removed in Shapely 2.0. Check the length of the `geoms` property instead to get the  number of parts of a multi-part geometry.

But you can ignore it, it still draws the points:

Full code:

---
title: "Reprex"
output: html_document
---

```{r setup, include=FALSE}
library(knitr)
library(reticulate)
knitr::knit_engines$set(python = reticulate::eng_python)
```

```{python}
from shapely.geometry import Point, LineString, Polygon, MultiPoint

point1 = Point(2.2, 4.2)
point2 = Point(7.2, -25.1)
point3 = Point(9.26, -2.456)
point3D = Point(9.26, -2.456, 0.57)

multipoints = MultiPoint([point1, point2, point3, point3D])
svg = multipoints._repr_svg_()

# or, in your case

svg = point1._repr_svg_()
```

```{r}
htmltools::HTML(py$svg)
```

How to display a geometric object from Python code in a Rmarkdown document?

1 Answers1