polar | PorarSSL - OpenSSL compatibility layer | TLS library

I'm trying to categorize the type of jigsaw puzzle pieces (number of heads, if it is a border or a corner...) by analyzing their contours.

The approach I'm trying to follow is analyzing this type of plot (from this paper) that "unwinds" the cartesian coordinates of the contours of the puzzle piece by converting it to polar coordinates; however I'm not able to replicate it.

I've tried with:

in pandas , i can run the code like:

I'm making a polar-transformed barplot in which several of the x-axis labels overlap with the plot area. For context, I'm working on a shiny application that you can find a copy of here.

I've tried using theme(axis.text.x = element_text(vjust = -someNumber)), but it doesn't seem to be doing anything.

Here is a reproducible example to demonstrate the problem:

I'm working on an interactive, polar ggplot bar with polar coordinates. The end goal is for the bars in each segment to 'rise' to meet the position of a mouse click in that sector.

The trouble is that click data for polar ggplots is cartesian, rather than polar: The bottom-left of the plot is c(0,0), rather than the centre. How can I get around this problem? Is there a simple coordinate transform I could use, or an option I could set?

You can see a prototype of the app here, and my code is below:

I am drawing polar chart with chart.js ^2.8.0 and ng2-charts ^2.3.0 in Angular. I have used chartjs-plugin-datalabels to display labels but this does not support lables outside at fixed positions outside the polar chart rings like this plugin for chart.js display labels outside the pie chart.

CODE:

I am developing an Sports Mobile App with flutter (mobile client) that tracks it's users activity data. After tracking an activity (swimming, running, walking ...) it calls a REST API developed by me (with springboot) passing that activity data with a POST. Then, my user will be able to view the logs of his tracked activities calling the REST API with a GET.

As I know that my own tracking development isn't as good as Strava, Garmin, Huawei and so on ones, I want to let my app users to connect with their Strava, Garmin and so on accounts to get their activities data, so I need users to authorize my app to get that data using OAuth.

In a first approach, I have managed to develop all the flow of OAuth with flutter using the Authorization Code Grant. The authorization server login is launched by flutter in a user agent (chrome tab), and once the resource owner has done the login and authorize my flutter app, my flutter app takes the authorization code and the calls to the authorization server to get the tokens . So I can say, that my client is my flutter App. When the oauth flow is done, I send the tokens to my Rest API in order to store them in a database.

My first idea was to send those tokens to my backend app in order to store them in a database and develop a process that takes those tokens, consult resource servers, parses each resource server json response actifvities to my rest API activity model ones and store in my database. Then, if a resource owner consults its activities calling my Rest API, he would get a response with all the activities (the mobiles app tracked ones + Strava, Garmin, resource servers etc ones stores in my db).

I have discarded the option to do the call to the resource servers directly from my client and to my rest api when a user pushes a syncronize button and mapping those responses directly in my client because I need the data of those resource servers responses in the backend in order to implement a medal functionality. Further more, Strava, Garmin, etc have limits of usage and I don't want to let my resource owners the hability to push the button the times they want.

Here is the flow of my first idea:

Steps:

1. Client calls the authorization server launching a user agent to an oauth login. In order to make the resource owner login and authorize. The url and the params are hardcoded are hardcoded in my client.

2. Resource owner logins and authorize client.

3. Callback is sent with code.

4. Client captures code of the callback and makes a post to he authorization server to get the tokens. As some authorization servers accept PKCE, I am using PKCE when its possible, to avoid attacks and hardcoding my client secret in my client. Others like Strava's, don't allow PKCE, so I have to hardcode the client secret in my client in order to get the tokens.

5. Once the tokens are returned to my client, I send them to my rest api and store in a database identifying the tokens resource owner.

To call the resource server:

1. One periodic process takes the tokens of each resource owner and updates my database with the activities returned from each resource server.

2. The resource owner calls the rest api and obtains all the activities.

The problem to this first idea is that some of the authorization servers allow implementing PKCE (Fitbit) and others use the client secret to create the tokens (Strava). As I need the client secret to get the tokens for some of those authorization servers, I have hardcoded the secrets in the client and that is not secure.

I know that it is dangerous to insert the client secrets into the client as a hacker can decompile my client and get the client secret. I can't figure how to get the resource owner tokens of Strava without hardcoding the client secret if PKCE is not allowed in the authorization server.

As I don't want to hardcode my client secrets in my client because it is insafe and I want to store the tokens in my db, I dont see my first approach as a good option. Further more, I am creating a POST request to my REST API in order to store the access token and refresh token in my database and if i am not wrong, that process can be done directly from the backend.

I am in the situation that I have developed a public client (mobile app) that has hardcoded the client secrets because I can't figure how to avoid doing that when PKCE isn't allowed by the authorization server to get the tokens.

So after thinking on all those problems, my second idea is to take advantage of my REST API and do the call to the authorization server from there. So my client would be confidential and I would do the OAuth flow with a Server-side Application.

My idea is based on this image.

In order to avoid the client secret hardcoding in my mobile client, could the following code flow based on the image work and be safe to connect to Strava, Garmin, Polar....?

Strava connection example:

MOBILE CLIENT

• Mobile public Client Calls my Rest API to get as a result the URI of Strava Authorization server login with needed params such as: callback, redirect_uri, client_it, etc.

• Mobile client Catches the Rest API GET response URI.

• Mobile client launches a user agent (Chrome custom tab) and listen to the callback.

USER AGENT

• The login prompt to strava is shown to the resource owner.

• The resource owner inserts credentials and pushes authorize.

• Callback is launched

MOBILE CLIENT

• When my client detects the callback, return to client and stract the code from the callback uri.

• Send that code to my REST API with a post. (https://myrestapi with the code in the body)

REST API CLIENT

• Now, the client is my REST API, as it is going to be the one that calls the authorization server with the code obtained by the mobile client. The client will take that code and with the client secret hardcoded in it will call to the Authorization server. With this approach, the client secret is no more in the mobile client, so it is confidential.

• The authorization server returns the tokens and I store them in a database.

THE PROCESS

• Takes those tokens from my database and make calls to the resource servers of strava to get the activities. Then parses those activities to my model and stores them into the database.

Is this second approach a good way to handle the client secrets in order to avoid making them public? Or I am doing something wrong? Whatr flow could I follow to do it in the right way? I am really stuck with this case, and as I am new to OAuth world I am overwhelmed with all the information I have read.

I am trying to change the color of individual polar chart rings using chart.js version and ng2-charts in Angular but in the documentation of particular versions, I haven't found anything related to it and neither searching the solution on web.

Is there a smart way to recursively generate matrices with increasing sizes in numpy? I do have a generator matrix which is

I try to do a bar plot, with an X axis a bit different than usual. The idea is to represent this axis by the initial variable (code) and by a grouping variable (region). Each code has one region attributed to it. And I would like vertical line to delimitate my regions on the plot.

Here is a reprex