change some nbviewer links to github

README.md

@@ -145,9 +145,9 @@ Tuesday | Thursday
 -----
 
 ### Class 5: Visualization
-* Python homework with the Chipotle data due ([solution](code/03_python_homework_chipotle.py), [detailed explanation](http://nbviewer.ipython.org/github/justmarkham/DAT8/blob/master/notebooks/03_python_homework_chipotle_explained.ipynb))
+* Python homework with the Chipotle data due ([solution](code/03_python_homework_chipotle.py), [detailed explanation](notebooks/03_python_homework_chipotle_explained.ipynb))
 * Part 2 of Exploratory Data Analysis with Pandas ([code](code/04_pandas.py))
-* Visualization with Pandas and Matplotlib ([code](code/05_pandas_visualization.py), [notebook](http://nbviewer.ipython.org/github/justmarkham/DAT8/blob/master/notebooks/05_pandas_visualization.ipynb))
+* Visualization with Pandas and Matplotlib ([code](code/05_pandas_visualization.py), [notebook](notebooks/05_pandas_visualization.ipynb))
 
 **Homework:**
 * Your project question write-up is due on Thursday.

homework/13_cross_validation.md

@@ -1,6 +1,6 @@
 ## Class 13 Pre-work: Cross-validation
 
-Watch my video on [cross-validation](https://www.youtube.com/watch?v=6dbrR-WymjI) (36 minutes), and be prepared to **discuss it in class** on Tuesday. The [notebook](http://nbviewer.ipython.org/github/justmarkham/DAT8/blob/master/notebooks/13_cross_validation.ipynb) shown in the video is also in this repository.
+Watch my video on [cross-validation](https://www.youtube.com/watch?v=6dbrR-WymjI) (36 minutes), and be prepared to **discuss it in class** on Tuesday. The [notebook](../notebooks/13_cross_validation.ipynb) shown in the video is also in this repository.
 
 Alternatively, read section 5.1 of [An Introduction to Statistical Learning](http://www-bcf.usc.edu/~gareth/ISL/) (11 pages).
 

project/README.md

@@ -23,7 +23,7 @@
     * [Final presentation](https://github.com/justmarkham/DAT-project-examples/blob/master/pdf/crime_presentation.pdf) by Debbie Yu
     * [Final presentation](https://github.com/justmarkham/DAT-project-examples/blob/master/pdf/dota_presentation.pdf) and [final paper](https://github.com/justmarkham/DAT-project-examples/blob/master/pdf/dota_paper.pdf) by Kyle Pomerleau
     * [Final paper](https://github.com/justmarkham/DAT-project-examples/blob/master/pdf/nba_paper.pdf) by Kerry Jones
-    * [Final paper](http://nbviewer.ipython.org/github/mikeyea/DAT7_project/blob/master/final%20project/Class%20Project.ipynb) by Mike Yea
+    * [Final paper](https://github.com/mikeyea/DAT7_project/blob/master/final%20project/Class%20Project.ipynb) by Mike Yea
 
 ## Overview