---------- Forwarded message ---------- From: . <mdzafir.alv...@gmail.com> Date: Thu, Apr 21, 2016 at 2:35 AM Subject: Request for correcting wrong Information on website To: apa...@apache.org
Dear site admin , I was browsing this page below : https://commons.apache.org/proper/commons-math/userguide/complex.html Between /* */ I am copy pasting some lines from the page . After this /**/ mark i will post error and corrections /* The Complex class provides basic unary and binary complex number operations. These operations provide the means to add, subtract, multiply and divide complex numbers along with other complex number functions similar to the real number functions found in java.math.BigDecimal: Complex lhs = new Complex(1.0, 3.0); Complex rhs = new Complex(2.0, 5.0); Complex answer = lhs.add(rhs); // add two complex numbers answer = lhs.subtract(rhs); // subtract two complex numbers answer = lhs.abs(); // absolute value answer = lhs.conjugate(rhs); // complex conjugate 7.3 Complex Transcendental Functions Complex <https://commons.apache.org/proper/commons-math/apidocs/org/apache/commons/math3/complex/Complex.html> also provides implementations of serveral transcendental functions involving complex number arguments. These operations provide the means to compute the log, sine, tangent, and other complex values : Complex first = new Complex(1.0, 3.0); Complex second = new Complex(2.0, 5.0); Complex answer = first.log(); // natural logarithm. answer = first.cos(); // cosine answer = first.pow(second); // first raised to the power of second */ First error : see the line : ------> answer = lhs.abs(); // absolute value answer was declared in complex previously , so you must capture the reply of lhs.abs() to a double variable correct: double answer = lhs.abs(); or double ans = lhs.abs(); // we have already declared a variable name //answer , so save this with a variable of different name Error 2 : see this line --> answer = lhs.conjugate(rhs); // complex conjugate Note that , Conjugate is a one input function , If z = 2+3i is a complex , conjugate is 2-3i , Here you pushed 2 complex ( lhs , rhs ) instead of one conjugate ( either lhs or rhs ) . So this generates error Correct : either : answer = lhs.conjugate(); or: answer = rhs.conjugate(); both are correct If you think by chance I am wrong , you can even check javadoc of your library , everything was correct there , but the example on this web is wrong only. Thats all I had to say. I am a great fan of your library Apache Commons Math 3.6.1 I was working on a project , in this project I needed to use common math .jar . It helped me a lot by saving time of many hard implementations . As a fan , I request you to correct this information as soon as possible . Thanks in advanced . - From one of your fans - Alvi
