heatmap.2(x=mat)```![在这里插入图片描述](https://i-blog.csdnimg.cn/direct/074758fc806b4a149f340decbd16da64.png)## Using north arrow and scalebar
```r
ggplot()+annotation_spatial(longlake_waterdf)+layer_spatial(longlake_depthdf, aes(col = DEPTH_M))+annotation_scale(location ="tl")+annotation_north_arrow(location ="br", which_north ="true")