How to evaluate a function on Imported data (.xlsx file)

I have imported an excel file, and I want to evaluate an expression on each point:

Data = Import["data.xlsx"] which gives output like this:

{{f,t},{2,12},{3,200},{20,2500},{38,100},{40,2000}} 

I want to evaluate following expression for each point:

Rate=EXP[(a-f)]*f*t 

where, a is some type constant. So far I am trying to use Evaluate function in mathemtica:

Evaluate[Rate, Data[[All, {1, 2}]]] Evaluate[Rate, Data[[All, {3, 4}]]] 

But couldn’t figure out how to obtained values for expression (Rate) for each value. Any help will be appreciated.

How to hypothesise, evaluate and communicate UI changes

I’m looking at compiling a spread sheet to compare React frameworks. (React Semantic UI, Material UI, Ant Design…).

Framework, metric...     Semantic UI                      Material UI                      Ant Design                       

There are some metrics which are un-opinionated tangible metrics (File size, Webpack Tree shaking, No. components) But these don’t necessarily communicate the value to the user.

Some things like Material UI (which I’m biased to) have really nice user feedback animations. I’d like to practice better UX and pragmatically evaluate these frameworks for our business use case.

How do I measure these very opinion oriented types of behaviours? Preferably without pushing to production. And communicate these findings to stakeholders?

Perhaps a more basic form of my question is “How to hypothesise the colour blue is better suited to our needs” How do I go about building a case for something design oriented like this.

System.InvalidOperationException(An exception was thrown while attempting to evaluate a LINQ query parameter expression)

I don’t know what’s wrong with my LINQ query, everything looks fine but I got above error on the following code: if (!dbcontext.AndroidUser.Any(user => user.Equals(value.UserName))) Here’s my complete code for RegisterController.cs.

 using System;  using System.Collections.Generic;  using System.Linq;  using System.Text;  using System.Threading.Tasks;  using APITesting.Models;  using APITesting.Utils;  using Microsoft.AspNetCore.Mvc;  using Newtonsoft.Json;   namespace APITesting.Controllers  {  [Route("api/[controller]")]  public class RegisterController : Controller  { NoNameRestaurantContext dbcontext = new NoNameRestaurantContext();  // POST api/<controller> [HttpPost] public string Post([FromBody]AndroidUser value) {     //First we need to check that user is existing in database.     if (!dbcontext.AndroidUser.Any(user => user.Equals                (value.UserName)))     {         AndroidUser user = new AndroidUser();         user.UserName = value.UserName;         user.Hash = Convert.ToBase64String(Common.GetRandomHash(16));         user.Password = Convert.ToBase64String(Common.HashPassword(             Encoding.ASCII.GetBytes(value.Password),             Convert.FromBase64String(user.Hash)));          //Save to Database          try         {             dbcontext.Add(user);             dbcontext.SaveChanges();             return JsonConvert.SerializeObject("Register Successfully");         }         catch (Exception ex)         {             return JsonConvert.SerializeObject(ex.Message);         }     }     else     {         return JsonConvert.SerializeObject("User is existing in Database");     }    }   }  } 

and for Common.cs class that I used to convert my password to hashPassword.

 using System;  using System.Collections.Generic;  using System.Linq;  using System.Security.Cryptography;  using System.Threading.Tasks;   namespace APITesting.Utils  {  public class Common  { /*  *   * FUNCTION TO CREATE RANDOM HASH STRING  *   */ public static byte[] GetRandomHash(int length) {     var random = new RNGCryptoServiceProvider();     byte[] hash = new byte[length];     random.GetNonZeroBytes(hash);     return hash; } /*  *   * FUNCTION TO CREATE PASSWORD WITH HASH  *   */ public static byte[] HashPassword(byte[] password, byte[] hash) {     HashAlgorithm algorithm = new SHA256Managed();     byte[] plainTextWithHashByte = new byte[password.Length + hash.Length];     for (int i = 0; i < password.Length; i++)     {         plainTextWithHashByte[i] = password[i];     }     for (int i = 0; i < hash.Length; i++)     {         plainTextWithHashByte[password.Length + i] = hash[i];     }     return algorithm.ComputeHash(plainTextWithHashByte);   }  } } 

I am following this tutorial: https://www.youtube.com/watch?v=b6T0_j7I9CE

How to evaluate the work of developers? [on hold]

I studied computer science about 10years ago but didn’t work in something related with computer science afterwards. Now i need to hire python developers to work on a project for a personal project but I am not sure how to best asses their skill.

What do you think are the best thing to look out for in the code to know if someone is doing a good job vs not so good? especially in python.

Thanks for all your tips 🙂

How to Evaluate the Best Tech for a Project [duplicate]

This question already has an answer here:

  • If there are two ways of approaching a task, how should one choose between them? 2 answers

I hope this question isn’t too subjective for SE, but I feel that a precise answer or approach can be given.

First off, I have spent some time researching this issue but I am posting the question here to gain some addition (and hopefully more thorough) advice.

I meet with a small group of devs to work on little side projects. We all have different backgrounds and understand technologies at different levels. One of the most difficult things for us is determining which programming language is best for a project.

So far I’ve determined these factors to be some of the most important:

What are the application needs (speed, stability, etc.) What features will the app have Scalability Security needs I’m wondering if anyone has a specific approach to selecting a programming language for a project.

Although this is a general question I’ll provide a specific project example. My group has decided to build a eSommelier. We could use React and make a website which can be accessed from many devices. We could use Swift and make an app for an Ipad. We could also use Python and program a tablet to run just this one application.

How to Evaluate the Best Tech for a Project [duplicate]

This question already has an answer here:

  • If there are two ways of approaching a task, how should one choose between them? 2 answers

I hope this question isn’t too subjective for SE, but I feel that a precise answer or approach can be given.

First off, I have spent some time researching this issue but I am posting the question here to gain some addition (and hopefully more thorough) advice.

I meet with a small group of devs to work on little side projects. We all have different backgrounds and understand technologies at different levels. One of the most difficult things for us is determining which programming language is best for a project.

So far I’ve determined these factors to be some of the most important:

What are the application needs (speed, stability, etc.) What features will the app have Scalability Security needs I’m wondering if anyone has a specific approach to selecting a programming language for a project.

Although this is a general question I’ll provide a specific project example. My group has decided to build a eSommelier. We could use React and make a website which can be accessed from many devices. We could use Swift and make an app for an Ipad. We could also use Python and program a tablet to run just this one application.