Unverified Commit 8c0254e9 authored by Maxim Belkin's avatar Maxim Belkin
Browse files

01-numpy.md: avoid numerical errors in lesson



The second weight (57.5) used in 01-numpy.md was also causing
numerical errors in Python 3. To avoid that, we change this
weight to 65.0
Signed-off-by: default avatarMaxim Belkin <maxim.belkin@gmail.com>
parent 1e2b92c8
......@@ -81,13 +81,13 @@ we can print several things at once by separating them with commas.
We can also change a variable's value by assigning it a new one:
~~~
weight_kg = 57.5
weight_kg = 65.0
print('weight in kilograms is now:', weight_kg)
~~~
{: .language-python}
~~~
weight in kilograms is now: 57.5
weight in kilograms is now: 65.0
~~~
{: .output}
......@@ -101,14 +101,14 @@ For example,
let's store the subject's weight in pounds in a variable:
~~~
#There are 2.2 pounds per kilogram.
# There are 2.2 pounds per kilogram
weight_lb = 2.2 * weight_kg
print('weight in kilograms:', weight_kg, 'and in pounds:', weight_lb)
~~~
{: .language-python}
~~~
weight in kilograms: 57.5 and in pounds: 126.5
weight in kilograms: 65.0 and in pounds: 143.0
~~~
{: .output}
......@@ -123,7 +123,7 @@ print('weight in kilograms is now:', weight_kg, 'and weight in pounds is still:'
{: .language-python}
~~~
weight in kilograms is now: 100.0 and weight in pounds is still: 126.5
weight in kilograms is now: 100.0 and weight in pounds is still: 143.0
~~~
{: .output}
......@@ -148,7 +148,7 @@ This is different from the way spreadsheets work.
> Variable Type Data/Info
> --------------------------------
> weight_kg float 100.0
> weight_lb float 126.5
> weight_lb float 143.0
> ~~~
> {: .output}
{: .callout}
......@@ -198,10 +198,10 @@ array([[ 0., 0., 1., ..., 3., 0., 0.],
The expression `numpy.loadtxt(...)` is a [function call]({{ page.root }}/reference/#function-call)
that asks Python to run the [function]({{ page.root }}/reference/#function) `loadtxt` which belongs to the `numpy` library.
This [dotted notation]({{ page.root }}/reference/#dotted-notation) is used everywhere in Python:
the thing that appears before the dot contains the thing that appears after.
the thing that appears before the dot contains the thing that appears after.
As an example, John Smith is the John that belongs to the Smith family,
We could use the dot notation to write his name `smith.john`,
We could use the dot notation to write his name `smith.john`,
just as `loadtxt` is a function that belongs to the `numpy` library.
`numpy.loadtxt` has two [parameters]({{ page.root }}/reference/#parameter):
......@@ -232,7 +232,7 @@ data = numpy.loadtxt(fname='inflammation-01.csv', delimiter=',')
~~~
{: .language-python}
This statement doesn't produce any output because we've assigned the output to the variable `data`.
This statement doesn't produce any output because we've assigned the output to the variable `data`.
If we want to check that the data have been loaded,
we can print the variable's value:
......@@ -821,7 +821,7 @@ the graphs will actually be squeezed together more closely.)
{: .callout}
> ## Check Your Understanding
>
> What values do the variables `mass` and `age` have after each statement in the following program?
> What values do the variables `mass` and `age` have after each statement in the following program?
> Test your answers by executing the commands.
>
> ~~~
......@@ -1224,7 +1224,7 @@ the graphs will actually be squeezed together more closely.)
> > ~~~
> > {: .language-python}
> >
> > If inflammation values *decrease* along an axis, then the difference from
> > If inflammation values *decrease* along an axis, then the difference from
> > one element to the next will be negative. If
> > you are interested in the **magnitude** of the change and not the
> > direction, the `numpy.absolute()` function will provide that.
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment