{
"cells": [
{
"cell_type": "markdown",
"id": "c8f27d2e",
"metadata": {},
"source": [
"# Using `geom_imshow()` to draw DEM on map\n",
"\n",
"[SRTM1N00E012V3](https://earthexplorer.usgs.gov/scene/metadata/full/5e83a3ee1af480c5/SRTM1N00E012V3/) courtesy of the U.S. Geological Survey"
]
},
{
"cell_type": "code",
"execution_count": 1,
"id": "86e9b69b",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:32.954683Z",
"iopub.status.busy": "2025-11-05T13:47:32.954584Z",
"iopub.status.idle": "2025-11-05T13:47:32.981696Z",
"shell.execute_reply": "2025-11-05T13:47:32.981306Z"
}
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"The geodata is provided by © OpenStreetMap contributors and is made available here under the Open Database License (ODbL).\n"
]
}
],
"source": [
"import numpy as np\n",
"from PIL import Image\n",
"\n",
"from lets_plot import *\n",
"from lets_plot.geo_data import *"
]
},
{
"cell_type": "code",
"execution_count": 2,
"id": "fe649753",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:32.982773Z",
"iopub.status.busy": "2025-11-05T13:47:32.982697Z",
"iopub.status.idle": "2025-11-05T13:47:32.984640Z",
"shell.execute_reply": "2025-11-05T13:47:32.984405Z"
}
},
"outputs": [
{
"data": {
"text/html": [
"\n",
" \n",
" \n",
" "
]
},
"metadata": {},
"output_type": "display_data"
}
],
"source": [
"LetsPlot.setup_html()"
]
},
{
"cell_type": "code",
"execution_count": 3,
"id": "43462276",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:32.985645Z",
"iopub.status.busy": "2025-11-05T13:47:32.985574Z",
"iopub.status.idle": "2025-11-05T13:47:32.987213Z",
"shell.execute_reply": "2025-11-05T13:47:32.986971Z"
}
},
"outputs": [],
"source": [
"def get_dem_data(url):\n",
" import requests\n",
" from osgeo import gdal\n",
" r = requests.get(url)\n",
" vsipath = '/vsimem/dem'\n",
" gdal.FileFromMemBuffer(vsipath, r.content)\n",
" return gdal.Open(vsipath)"
]
},
{
"cell_type": "code",
"execution_count": 4,
"id": "198ce722",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:32.988048Z",
"iopub.status.busy": "2025-11-05T13:47:32.987982Z",
"iopub.status.idle": "2025-11-05T13:47:32.989345Z",
"shell.execute_reply": "2025-11-05T13:47:32.989111Z"
}
},
"outputs": [],
"source": [
"plot_size = 600\n",
"subplot_size = 500"
]
},
{
"cell_type": "code",
"execution_count": 5,
"id": "73c3ab3c",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:32.990077Z",
"iopub.status.busy": "2025-11-05T13:47:32.990013Z",
"iopub.status.idle": "2025-11-05T13:47:34.116817Z",
"shell.execute_reply": "2025-11-05T13:47:34.116342Z"
}
},
"outputs": [],
"source": [
"# Data from geocoding\n",
"states = geocode_states().scope(\"Gabon\").inc_res(4).get_boundaries()\n",
"cities = geocode_cities().scope(\"Gabon\").get_centroids()"
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "45972976",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:34.118193Z",
"iopub.status.busy": "2025-11-05T13:47:34.118078Z",
"iopub.status.idle": "2025-11-05T13:47:35.857914Z",
"shell.execute_reply": "2025-11-05T13:47:35.857337Z"
}
},
"outputs": [],
"source": [
"# Data from DEM\n",
"dataset = get_dem_data(\"https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/ivindo_river.tif\")\n",
"dataset_array = dataset.ReadAsArray()\n",
"transform = dataset.GetGeoTransform()\n",
"lon_min = transform[0]\n",
"lon_max = lon_min + (transform[1] * dataset_array.shape[1])\n",
"lat_max = transform[3]\n",
"lat_min = lat_max + (transform[5] * dataset_array.shape[0])"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "c233fae5",
"metadata": {
"execution": {
"iopub.execute_input": "2025-11-05T13:47:35.859461Z",
"iopub.status.busy": "2025-11-05T13:47:35.859369Z",
"iopub.status.idle": "2025-11-05T13:47:38.069495Z",
"shell.execute_reply": "2025-11-05T13:47:38.069262Z"
}
},
"outputs": [
{
"data": {
"text/html": [
" \n",
"