## Create Bins and View Distributions

I have just enrolled in a Data Science course on Udemy  and I learned good stuff.

It’s cool, you finished the 1st part. Now we’re going to do more deep Data Mining analysis with this bank’s dataset.

To make these analyzes more deep, we’ll create a more statistical approach.

To do that we will create a new tab.

For this new tab, we want to understand how client distributed according to their age. Is there a majority of young or old people ?

Move the variable « Age » in « Columns ».

As we want to see the distribution of client ages, we need to use the variable « Number of Records » to see the number of observations. Move the variable « Number of Record » to « Rows ».

Boom, we have a chart but there is only one point on the top right. What happened is that Tableau took the sum of the ages of all the bank’s clients and the sum of all the « Number of Records », it means the total number of clients, 10 000 clients.

We’ll find a solution but before we’ll change the format to better see the chart. Right-click in the middle of the chart and select « Format ».

For the font’s size, select « 12 ».

Here you can see that the total age is 39 218 but that’s not what we’re looking for. What we want to see is the number of clients for each age.

I’ll explain what’s going on. We took the aggregated sums of our variables. Aggregate means that we took the total sum of the variable for each category. We added the ages but in fact we want to see the total number of observations for each age separately.

To have that, just click on the arrow in « SUM(Age) » in « Columns ».

Then select « Dimensions »

You see, Tableau doesn’t take the aggregated sum of ages but it takes ages separately. We have a curve that shows us the continuous distribution of our clients ages. That is to say, for each age, the curve gives is the number of clients of this age.

We’ll look at the dataset. Right-click on « Churn Modelling » and select « View Data… ».

There is window that appears that shows us the data in detail. If you scroll to the right, you will find the column « Age ».

We see that the ages rounded. As all ages rounded, Tableau is able to group clients by age. By positioning the mouse on the curve, we can see that there are 200 clients who are 26 years old.

If in the dataset, ages weren’t rounded, you would have seen clients with 26.5 or 26.3 years. It would create a lot of irregularity, there would be plenty of spikes with lots of variations.

Oooooh look, there is a variation that isn’t normal.

Let’s analyze it in detail. Around this peak, we see that there are 348 clients who are 29 years old.

Here, 404 clients who are 31 years old.

And this peak down that shows us that there are 327 clients who are 30 years old.

How to explain this irregularity ? It’s possible that many people of 29 years old are about to turn 30 years old and many people of 31 years old who just had 31 years old. It’s chance that make us have inaccuracies. You may have other inaccuracies if you data isn’t precise and rounded. In our case, the ages are rounded but we want to get rid of our small irregularity that we see on our curve.

There is way to see our distribution without our irregularities, it’s « bins ». « Bins » consists of grouping the information into different categories. That is we’re going to regroup our clients in different age groups.

Right-click on « Age » in « Measures ». Select « Create » and select « Bins… ».

A window appears. We’ll group our clients in 5-years increments. In « Size of bins », write « 5 » and click on the « OK » button.

As you can see, the variable « Age » has remained in « Measures » but there is a new variable in « Dimensions ».This is the variable we created « Age(bins) ».

Our « Age(bins) » variable was correctly placed in « Dimensions » because it is a category variable because each category corresponds to a 5-year age group.

For example, one category is 20 to 24 age group. Now we’ll create a new distribution based on « bins ».

To do that, we’ll remove the variable « Age » from « Columns » with a click and drag outside.

You move the variable « Age(bins) » from « Dimensions » to « Columns ».

Note

In this case, it’s not possible to directly replace « Age » by « Age(bins) » over « Age » on « Columns ». This is because « Age » is a measure and « Age(bins) is a dimension.

That’s nice distribution, it’s usually the type of distribution (chart) we see in economics or mathematics. The difference with the old chart is that this chart is discrete. This chart is discrete because the clients grouped by age group while the previous chart was continuous.

On this distribution (chart), each bar corresponds to an age range. For example, this bar corresponds to the 25-29 age group.

Now, we’ll change the colors.

In « Row », move « SUM(Number of Record) » while holding down the « Ctrl » or « Command » key on your keyboard to « Colors ».

We get our distribution in blue but we’ll change the color to red. Click on « Colors » and click on « Edit Colors »

In the window that appears, click on the blue square on the right to display the color pallet.

Select the red color and click on the « OK » button.

Click on the « OK » button of the « Edit Colors » window.

To facilitate the reading of the bar chart, we’ll add the number of clients in each age group. In « Row », move « SUM (Number of Record) » while holding the « Ctrl » or « Command » key on your keyboard to « Label ».

That’s it, we can see how many clients there are in each age group.

We see that the dominant bar is the 35-39 age bracket and the second dominant bar is the 30-34 age bracket. Overall, we can see that most clients are between 25 and 40 years old, which seems consistent.

On our bar chart, we have absolute values. We’ll replace that with percentages. Click in the little arrow in « SUM(Number of Records) » in « Label » and you select « Add Table Calculation… » but I’ll show you another way to do it.

Instead of clicking « Add Table Calculation… », click on « Quick Table Calculation » and select « Percent of total ».

It’s cool, we have the exact percentage of people in each age bracket. Now, we can see that in the 25 to 40 age group, we have 20 + 23 +17= 60% of clients.

I’ll show you one last thing.You can change the size of the slices easily, just click on « Age(bins) » and select « Edit ».

In the windows, you can change the size of the slices (bins). Put « 10 » instead of « 5 » to get 10-years slices. Click on the « OK » button.

Now, we have a distibution with fewer slices and the dominant slice is 30 to 39 years old.

Well, it was just to show you how to change the size of bins. To go back to the old distribution with the 5-years slices, click on « Back » button.

As you can see, the values on bars are in percentages but the values on the axis are in absolutes values. Here is an exercise that I ask you to do : « Put the values of the axis in percentage ». I’ll give you the answer the next article.

-Steph

## Spinal Disc Herniation

I read a Frederic Delavier’s book « Strength Training Anatomy » and I learned good stuff.

First we can say : « disc herniation » or « herniated disc » but I prefer use « disc herniation » in my article.

Disc herniation is a common pathology in bodybuilding. This often occurs because of poor back placement during exercises such as squat, deadlift and rows (barbell bent row, seated row, etc).

During the execution of theses exercises, the main defect observed is the rounding of the back or a flexion of the spine. Because of that discs are pinched forward and loosened backward.

If an intervertebral disc cracked or aged, the gelatinous fluid of the nucleus pulposus moves backwards and can compress the spinal cord or roots of the spinal nerves. The symptoms of a disc herniation depends on the nature of the lesion, the amount of nucleus displaced and the surface that nucleus compresses.

The disc may have a bump or even worse, the nucleus may explode through the surrounding annulus fibrosus. It’s also possible that the posterior ligament that joins the vertebrae to each other is broken. The compressions caused by the rupture of the annulus fibrosus are always painful and incapacitating.

In bodybuilding, disc herniation are mainly at the lumbar level. Often between the 3rd and 4th lumbar vertebrae or between the 4th and 5th lumbar vertebrae. The pain is dull and deep and sometimes with numbness and tingling. Often the pain is in the middle of the back or on one side. The pain extends onto the glutes, pelvis and pubis. Sometimes pain can be felt throughout the leg following the path of the sciatic nerve because the sciatic nerve is compressed at the root (hence the name of sciatic to define this type of pain).

Usually disc herniation resolve spontaneously and the pain gradually disappears. But in some cases the bump on a vertebral disc doesn’t disappear and can continue to painfully pres on the nerves or it’s a loose piece of intervertebral cartilage that compresses the nervous elements.

In these 2 cases, the doctor will think of doing a surgical operation to remove the part that compresses the nerves.

To avoid having a disc herniation, it’s essential to do squat, deadlift, « good morning » and rows (rows, barbell bent row, seated row) with excellent positioning technique.

Attention

For all exercises done with very heavy weight, it’s necessary to perform a « blocking » :

1. Take a deep breath and block the breathing to fill the lungs like a balloon. This stiffens the ribcage and prevents the top of the torso form tilting forward.

2. Squeeze abs stiffens the belly, This increases the intra-abdominal pressure and prevents the torso from sagging forward.

3. By slightly arching the lower back with lumbar squeeze, this allows to have the spine’s bottom in extension.

These 3 simultaneous actions is what we call « blocking ». This « blocking » has the function of avoiding the rounding or bending of the spine because with very heavy weights, it can create disc herniations .

Note

After a training session with very heavy weights, it’s advisable to do stretching for the spine. There is an excellent exercise to relax the back muscles and rebalance the pressure inside the intervertebral discs. Click here .

For exercises such as deadlift or squat, it’s important not to round your back to avoid lower back injuries.

Disc herniation

Flexion of the spine with heavy weights can create disc herniations at the level of the lumbar vertebrae.

These disc herniations are common at squat and deadlift. This is caused by a bad back position during exercise. That’s why it’s important to work the technique for these exercises.

Disc herniation according to the age

From the age of 30 years old, intervertebral discs degenerate and don’t worry, it’s normal, The annulus can crack and the nucleus pulposus dries progressively.

Vertebral discs of people over 30 years old are more rigid, less elastic and the mobility of the spine is more limited. But as the viscous gel of the nucleus pulposus deacreases due to drying, the risk of the vertebral discs moving and compressing the nerves diminished.

Vertebral discs of people under 30 years old are more flexible, more elastic and there is more mobility with the spine. There is a greater amount of viscous gel in the nucleus pulposus which increases the risk that vertebral discs will move and compress the nerves. Disc herniation is very common among young athletes.

Share this article if you think it can help someone you know. Thank you

-Steph

## Navigate In Tableau

I have just enrolled in a Data Science course on Udemy  and I learned good stuff.

We’ll explore Tableau’s tools

From the connection manager, we’ll go into the Tableau’s workspace.

Click on the « Sheet1 » tab at the bottom of the window.

Here is the Tableau’s workspace.

The 2 important elements of the workspace are « Data » on the left and the workspace on the right. It’s in the workspace that you’ll create tables and charts.

We’ll start with « Data » on the left.

« Data » divided into 2 zones : dimensions and measures.

The dimensions and measures are 2 different rules that will allow you to manipulate data.

Tableau sets the numerical values in « measures » and the categorical or quantitative variables in « dimension ». This is the Tableau’s settings by default.

There is also another way to explain « dimension » and « measures ». The « dimensions » are independent variables and the « measures » are dependent variables.

For exemple, « Units » is a measure, it’s the number of items sold per product. « Region » is a dimension, it’s the geographic region where the product sold. With 2 elements we can know how many items sold by region. This means that « Region » is an independent variable and « Units » is a dependent variable because it will be grouped by region.

But if you don’t like it, you can move the entities between dimension and measures and the opposite by click and drag.

In the menu bar, at the top, there is « File » where you can open and save file.

« Data » to connect to new source files.

« Worksheet » is the workspace to create analyzes

« Dashboard » is a combination of worksheet

« Story » is a combination of worksheet and dashboard

« Analysis » to specify how you want to do your analysis on your workspace

« Map » to add maps to the workspace

« Format » contains formatting options

Now, let’s study the workspace.

In the workspace, the main elements are « Columns » and « Rows ». This is where you decide which data goes in columns and rows in your worksheet.

You can also choose different format for these elements like colors, size, text level of detail and tooltips (useful tool optional).

Let’s do a test. Use data from « Region » (which is in « dimension »). Move « Region » with a click and drop to the center of your workspace. Now, « Region » is in the element « Rows ».

A table appears in your workspace.

You put a dimension in your workspace. Now put a measure in your workspace.

Uses the « Units » data. Move « Units » with a click and drop next to the « Region » column.

As you can see, Tableau automatically put « Region » in the « Rows » element and the « Units » data aggregated by region. In this way, you can tell how many items were sold by region.

Now, what you can do is to move « SUM(Units) » to the « Columns » element.

And then, you have a « bar chart » to see how many items have been sold by region. You can enlarge the graphic with a click and drop.

Let’s look at the tools that are in « Show Me » zone.

Click on « Pie chart » to have this chart’s type.

Click on « Size » icon and drag from left to right you can increase the chart’s size.

In this chart, each region has a color and proportion of items sold by region.

You can also test the « bubble chart ». Tableau organizes the data automatically and everything and placed in the « Marks ».

You can test « Treemaps » chart. This is the same principle as « bubble chart » but it’s rectangles instead of circles.

As you can see in « Show Me », there are charts disabled. This is because you need some elelments in your data to be able to activate them.

For example for the « Area chart », you need « date »data to activate it.

Share this article if you think it can help someone you know. Thank you.

-Steph

## How To Do Upright Rows

I read a Frederic Delavier’s book « Strength Training Anatomy » and I learned good stuff.

Standing with your legs slightly apart and your back is straight. You hold the barbell with a pronated grip and the spacing of your hands is a palm’s width or a little more.

• Inhale and you pull the barbell along your body to your chin by raising your elbows as high as possible.

• Expire and return to the starting position by controlling the movement.

This exercise works mainly upper trapezius, deltoid and a little bit brachialis, brachioradialis, forearm flexors, abs, buttdock and sacrospinalis.

The more you put your hands apart, the more you work your deltoids and the less you work your trapezius.

Share this article if you think it can help someone you know. Thank you.

-Steph

## How To Do T-Bar Rows

I read a Frederic Delavier’s book « Strength Training Anatomy » and I learned good stuff.

Podcast:

Lying on the belly on the inclined bench and take the handles with a pronated grip :

• Inhale and brings the bar to your chest

• Exhale at the end of movement

This exercise is similar to the barbell bent rows but it allows a better work of the back muscles because there is less need to focus on the body’s positioning.

This exercise works latissimus dorsi, teres major, posterior deltoid, arm’s flexor (biceps, brachialis, and brachioradialis), rhomboids and trapezius.

The machines with a belly support allow to focus less on the positioning, abs and spinal erectors don’t work. When there are very heavy weights, the rib cage can be compressed on the ventral support and this hinders breathing. When it’s difficult to breathe, doing the exercise is unpleasant.

Note

With a supinated grip, this exercise especially works the brachialis and the upper part of the trapezius at the end to the pull.

Share this article if you think it can help someone you know. Thank you.

-Steph

## From Beginner To Become Your Own Personal Trainer (Part 1)

I read a Nerd Fitness article  and I learned good stuff.

Before to read this article, I advise you to read Find The Gym For Your Goals Part 1 et Part 2; Back To The Source Of Equipment Part 1 et Part 2; Back To The Source Of Human Strength Part 1 et Part 2.If you already read it, continue and have fun.

A strong body is a healthy body, you have heard this many times but it’s not easy to do. Starting a new workout can be intimidating. It’s, for this reason, a lot of people fail.

# How you will train

To start, you have to find out what kind of strength training you want to do. It depends on the equipment and your goals. Here are several types of training programs :

Bodyweight

With a bodyweight training, you need little equipment (or not at all) and you can train everywhere (home, hotel, playground, workplace). As long as you have room to move, you can train.

If you like bodyweight training, take a pull-up bar and a set of gymnastics rings. If you’re really a beginner, an exercise band  can assist you in the movement like pull ups and dips.

If is that you can do bodyweight training without equipment, the disadvantage is that you need to constantly change exercises difficult to be sure to progress.

Dumbbells

Dumbbells are excellent for starting a workout with weight for several reasons.

First, gyms always have a good set of dumbbells. If you want to train at home, you can buy a set of adjustable dumbbells (that’s how I started in my bedroom).

The second reason is that dumbbells allow you to add a small amount of weight to do an exercise and exercise with dumbells are less intimidating that exercise with a barbell. For example, if you’re a beginner, starting with a 20kg (45lbs) barbell is a bit too much.

Dumbbells also allow you to work your symmetry and allow you to balance the strength of your right side and left side of your body. It’s ridiculous to have an arm or a leg extremely bigger and stronger as the other.

If you can’t finish a repetition, it’s easy to throw dumbbells on the floor compared to a barbell. For a beginner, it’s excellent for learning movements.

The disadvantage is that to evolve, you need to buy new dumbbells and this can be expensive. A gym membership is handy to avoid this problem.

Barbells

If your goal is to gain only strength, this is the recommended option. Barbell allows you to progress cleanly and quickly by adding a small amount of weight each week.

A barbell is really stable because you use your 2 hands instead of 1 hand for dumbbells so it’s easy to lift heavy (especially for the lower body like squat of deadlift). For exercises like the squat or the press, you can use the rack to load and unload weights safety.

The disadvantage is that to do this at home, you need to have a squat rack, a barbell, a bench and enough weight plates in your house or in your garage. A gym membership is handy to avoid this problem.

What’s the best way to train?

The barbell is optimal for gaining strength. Bodyweight training is good but you have to seriously motivate you to train at home.

Sometimes you have to adapt to the situation to be able to do your training. When I travel a bodyweight training is perfect if I don’t have access to a gym.

But the best workout is when you lift heavy. Nothing can replace squat, deadlift and body weight pull up.

There are also other ways to have a strength training like rock climbing, yoga or parkour.

# Choose the program to follow

Never go to the gym without having a plan. To get results, it’s necessary to have a plan to track your progress.

For to make a lot of progress, a beginner can have a full body program of 3 times a week with a day off between training days. Be sure that the program you choose matches your goals, A powerlifters will have a different training from a bodybuilder or an endurance athlete.

In my article Back To The Source Of Human Strength Part 1 and Part 2, I talk about numbers of repetitions and their goals :

• Reps in the 1-5 range build super dense muscle and strength

• Reps in the 6-12 range build a somewhat equal amount of muscular strength and muscular endurance.

• Reps in the 12+ range build muscular endurance and size

Many beginner strength training programs say to do 5 sets of 5 repetitions to optimize progress to gain strength.

With a circuit or superset, you do a set of each exercise in an order and you repeat the process.

For example :

• 20 bodyweight squat

• 10 push ups

• 20 walking lunges

• 10 dumbell rows

• 15 second plank

• 30 jumping jacks

• Repeat all these 5 times to do 5 sets

In traditional strength program, you do a complete set of an exercise, you rest and you do another set of the same exercise and so on.

For example :

• 10 squat

• Rest

• 10 squat

• Rest

• 10 squat

• Rest

• 10 squat

• Rest

• 10 squat

• Next exercise

If your goal is to be healthy and lose weight, you don’t need to focus on strength, a circuit (superset) is perfect.

This allows you to spend less time at the gym and to make up your high heart rate longer.

If your goal is to have more strength and have more muscle, choose a traditional strength training.

One important thing, your diet corresponds to 80-90 % of your success or failure. The quality of your diet will help you gain strength and lose fat.

When you choose a workout to develop your strength, be sure to increase the difficulty over time. To become stronger, you need to write a plan. This can be to do one more squat, lift 2kg (5lbs) more or do your circuit (superset) 10 seconds faster.

The main goal is to always be better than the last time, this is what ensures the continuity of being stronger and faster.

You can write your own training program or fortunately, there is a lot of excellent beginner program.

Share this article if you think it can help someone you know. Thank you.

-Steph

## How To Do T-Bar Rows On Feet

I read a Frederic Delavier’s book « Strength Training Anatomy » and I learned good stuff.

Podcast

Knees slightly bent with the bar between your legs. Your take the handles with a pronated grip. Your back is straight and you incline your torso at about 45° :

• Inspires and brings the bar to your chest

• Exhale at the end of the movement

This exercise is similar to the barbell bent rows but it allows a better work of the back muscles because there is less need to focus on the body’s positioning.

This exercise works latissimus dorsi, teres major, infraspinatus, rhomboids, the middle part of trapezius and arm’s flexors (biceps, brachialis, and brachioradialis).

Incline your torso works your abs and spinal erectors isometrically.

With a supinated grip, this exercise especially works the brachialis and the upper part of trapezius at the end of the pull.

There are some machines that allow you to have a semi-pronation grip. With a semi-pronation grip, you intensely work the forearms muscles, especially the brachioradialis.

Share this article if you think it can help someone you know. Thank you.

-Steph