bimbo36

isn't this all about understanding how atoms works at its deepest levels ?? i am just a computer science student , i am not a physicist ... i still don't know what holds an electron to its place ... does this resemble atoms ? but after watching a lot of documentaries on quantum physics ... i ended up watching this documentary ... its not bad as it sounds ...

just a bit of an update of the last post ... i am adding one more text and some algorithm notes too , to it ... for example ... this is an instantaneous rate of change , find the function ... and the answer is a function that has the property of ,this instantaneous rate of change ... example 2 : this is an instantaneous rate of change ... find the function ,the solution , the answer which is a set of points that has certain underlying qualitative property which produced, this instantaneous rate of change ... #include<stdio.h> #include<math.h> main() { float x; /*defining variables*/ float y; float h; float targetx; puts("This program will solve the differential equation y' = y - x \nusing Euler's Method with y(0)=1/2 \n\n"); puts("Please enter the desired constant step size. (h-value)\n\n"); scanf("%f", &h); /* Defining step size*/ puts("\n\nNow enter the desired x-value to solve for y.\n\n"); scanf("%f", &targetx); y = 0.5; x = 0.0; puts("\n\nX Y"); while ( x != targetx ) { printf("\n\n%f %f", x, y); y = y + ((y - x)*h); x= x+h; } printf("\n\n%f %f\n", x, y); printf("\nThe value of y at the given x is %f.\n\n", y, h); system("pause"); } here the solution is a set of points or a table of values that has certain underlying qualitative property which produced, this instantaneous rate of change ... ??

blue89 , no problems ...i hope you will find what you are looking for ... good luck ...

blue89 , have you used Gnuplot ? i have not tried this program before .. and i don't even know if this is the sort of application you are looking for ... anyway i was a bit curious ... so i followed this tutorial here ... http://people.duke.edu/~hpgavin/gnuplot.html does this help ??

i am still confused about ceratin things ... i have few more doubts ... i was trying to learn "computer oriented numerical methods in c programming language " we had a messed up syllabus ... it was supposed to start with a program for a polynomial factorization first ... but i cannot even find one example program of a polynomial factorization in c in any texts or online... so i have been trying to re arrange the whole syllabus , so that it becomes something nice to look at and easy to learn ... i have been following at least this much amount of books to narrow it down ... for example ... this is an instantaneous rate of change , find the function ... and the answer is a function that has the property of ,this instantaneous rate of change ... example 2 : this is an instantaneous rate of change ... find the function ,the solution , the answer which is a set of points that has certain underlying qualitative property which produced, this instantaneous rate of change ... #include<stdio.h> #include<math.h> main() { float x; /*defining variables*/ float y; float h; float targetx; puts("This program will solve the differential equation y' = y - x \nusing Euler's Method with y(0)=1/2 \n\n"); puts("Please enter the desired constant step size. (h-value)\n\n"); scanf("%f", &h); /* Defining step size*/ puts("\n\nNow enter the desired x-value to solve for y.\n\n"); scanf("%f", &targetx); y = 0.5; x = 0.0; puts("\n\nX Y"); while ( x != targetx ) { printf("\n\n%f %f", x, y); y = y + ((y - x)*h); x= x+h; } printf("\n\n%f %f\n", x, y); printf("\nThe value of y at the given x is %f.\n\n", y, h); system("pause"); } here the solution is a set of points or a table of values that has certain underlying qualitative property which produced, this instantaneous rate of change ... ??

blue89, thanks a lot for all that helpful posts ... i have been trying to follow this book ..for sometime now ... i have managed it this far ... #include<stdio.h> #include<conio.h> #include<math.h> void main() { float x[10],y[10],temp=1,f[10],sum,p; int i,n,j,k=0,c; clrscr(); printf("\nhow many record you will be enter: "); scanf("%d",&n); for(i=0; i<n; i++) { printf("\n\nenter the value of x%d: ",i); scanf("%f",&x[i]); printf("\n\nenter the value of f(x%d): ",i); scanf("%f",&y[i]); } printf("\n\nEnter X for finding f(x): "); scanf("%f",&p); for(i=0;i<n;i++) { temp = 1; k = i; for(j=0;j<n;j++) { if(k==j) { continue; } else { temp = temp * ((p-x[j])/(x[k]-x[j])); } } f[i]=y[i]*temp; } for(i=0;i<n;i++) { sum = sum + f[i]; } printf("\n\n f(%.1f) = %f ",p,sum); getch(); } /* ______________________________________ OUT PUT ______________________________________ how many record you will be enter: 4 enter the value of x0: 0 enter the value of f(x0): 0 enter the value of x1: 1 enter the value of f(x1): 2 enter the value of x2: 2 enter the value of f(x2): 8 enter the value of x3: 3 enter the value of f(x3): 27 Enter X for finding f(x): 2.5 f(2.5) = 15.312500 */ #include<stdio.h> #include<math.h> main() { float x; /*defining variables*/ float y; float h; float targetx; puts("This program will solve the differential equation y' = y - x \nusing Euler's Method with y(0)=1/2 \n\n"); puts("Please enter the desired constant step size. (h-value)\n\n"); scanf("%f", &h); /* Defining step size*/ puts("\n\nNow enter the desired x-value to solve for y.\n\n"); scanf("%f", &targetx); y = 0.5; x = 0.0; puts("\n\nX Y"); while ( x != targetx ) { printf("\n\n%f %f", x, y); y = y + ((y - x)*h); x= x+h; } printf("\n\n%f %f\n", x, y); printf("\nThe value of y at the given x is %f.\n\n", y, h); system("pause"); } i think these root finding algorithms for polynomial equations does not involve factorization ... i think i should find more examples of equations to solve by numerical techniques involving polynomials and differential equations ... ??

i might be able to program all those 7 programs properly in Dev c++ ... i have few more doubts ... in certain equations why do we change the unit of x to delta x , and the unit of y to delta y ??

blue89, i have been trying hard to keep it as appropriate as possible ... using c language isn't exactly that easy either ... thanks for the replies ...

blue89, this thread is a bit of a mess ... i was trying to narrow it down with the help of some pictures ... we had this subject called "computer oriented numerical methods in c programming language " in the second semester ... that was the only maths related subject we had ... the rest was 12 programming languages ... the "computer oriented numerical methods in c programming language " looked a bit like this ... terms like "Solution of equations by iterative algorithms" were very confusing in the beginning ... now i am a little bit more familiar with all these terms ... thanks a lot for the replies ...

programming is a lot more harder than that ... on a usual case ... we are given problems like these only... i think it would be a good idea to focus on those 7 programs instead of going after the things outside the syllabus ...

thanks to you .. from now on i can focus a bit more on programming ... rather than spent all my time in front of mathematics ...

sorry for the long posts ... i was able to narrow it down to these ... An equation containing the derivatives of one or more dependent variables, with respect to one or more independent variables, is said to be a differential equation they are mainly classified into two .. ordinary differential equation partial differential equation .. then comes first order differential equations to nth order differential equations ... order is the highest number of the differentiations appearing degree is the power of the highest order derivative in the equation ... then there are types of differential equations , depending on their order separable equations homogeneous equations linear equations exact equations A partial differential equation is an equation involving functions and their partial derivatives ... In mathematics, a partial derivative of a function of several variables is its derivative with respect to one of those variables, with the others held constant i was very confused when i began studying this ... because i was mostly aiming for the numerical methods ...

blue89 , Thanks a lot for all the explanations ...

blue89 , thanks a lot for the replies ... your maths looks a bit too advanced to me ... i am a bsc computer science student ... and we had this "computer oriented numerical methods in c language " in college ... our practical lab , involved solving 7 questions with numerical methods... at that time , i was not aware of the depth of this subject ... since then , i have been trying to understand this ... my understanding so far is , that we are dealing with .... iterations of the "instantaneous rate of change " in the question ... at this point of time , i am not exactly sure how the algorithms , or the iteration properties affects the results ... finding delta y / delta x for an instantaneous rate of change is like already a step for approximating or finding function values ... i guess the euler's method is one such algorithm to take smaller intervals of the instantaneous rate of change in the question ... i have learned from your post that , the smaller the interval .. the much clearer the properties of the function we are trying to find ... ??

i like this sentence actually ... is iteration like another word for numerical methods ?? and we are trying to iterate the instantaneous rate of change ... in the question right ? and the Euler's method is one such iteration for ... the instantaneous rate of change in the question ... after these iterations with the help of these algorithms ... we get function values ... then if you increment x ... you get properties of that function again at certain points or places if you add all the function values ... you get the overall properties of a function ... and that is the function with all those properties that has given that instantaneous rate of change ... ??

i don't know if i am understanding this properly ... this thread , post # 8 ... picture one .. that question is about finding the "function" that has that instantaneous rate of change ... right ?? we found the function ... that has that rate of change ... same thread picture two , we are given a function and we are trying to solve it numerically ... if you take dy/dx of that instantaneous rate of change you get certain properties of that function at certain points or places ... then if you increment x ... you get properties of that function again at certain points or places if you add all the function values ... you get the overall properties of a function ... and that is the function with all those properties that has given that instantaneous rate of change ... ?? ??

unfortunately i only understand this part clearly ... i don't understand the importance of function values or what they actually mean ... ??

i have been trying to follow at least this much amount of books ... i have few doubts ... how to find an initial guess ... ?? i am also trying to understand the steps involved , in these two questions ... first we are given a gradient of the curve or an instantaneous rate of change then we are trying to find a function that is giving this gradient of the curve or this instantaneous rate of change then we change the dy/dx , the gradient of the curve or an instantaneous rate of change to ... delta y /delta x which is an even smaller gradient of the curve or a smaller instantaneous rate of change ... we start with x = 0 , we get y =0 when we increment x by 0.1 , we get the value of y around -0.299 which is another gradient of the curve for delta y / delta x , the smaller instantaneous rate of change why are we adding up these gradients of the curve or the smaller instantaneous rate of change for these small small change in delta y / delta x? this means that these smaller gradients of the curve or these smaller instantaneous rate of change has certain property at each value of x ..., the gradient of the curve with respect to x which is indeed "the rate" at which y is changing as x is changing .... so the function has the property of this "rate" ??? usually , when we try to solve ... we get a function that has this instantaneous rate of change ... but when we try to solve it with numerical methods , we only get a " rate " which is the property of that function ???

i am sorry for the long posts ... as i learn more , the size of the post seems to be getting smaller ... i really need to understand how these works ... lagrange's interpolation formula newton raphson method bisection method eulers method newtons forward runge kutta method trapezoidal rule and i dont have one text that explains it all ...

i am so confused ... what is this initial guess ?? the initial guess of what ??

?? like this ??

i am a computer science student ... not an expert programmer ... this is not an easy thing to do ... all those things requires a lot of programming... i don't know if these pictures might help you ... that was my own attempt to program something useful , with html , php , mysql , javascrip and ajax ... i had to play around with some scripts i downloaded from the internet ... the first picture is supposed to be the client side ... and the last picture is supposed to be a linux machine where you host your files...

my questions sort of looks a bit like this ... ??

i am sorry .. this is seriously one last time ... i collected notes like this from many different places and it took a lot of time to arrange it like this ... can i please keep it for one last time ?? i wont repeat this ... from next time onward i promise i would keep it short and neat ...

let me try to refresh this thread with few more things ... i am trying to put all the stuff from my syllabus in this thread , so that i don't have to look anywhere else ... my syllabus was called , "computer oriented numerical methods in c programming language " it had lot of mathematics ... it was a bit of a mess ... we really lacked proper texts and materials to really understand that subject .... none of the texts i have read had the proper mathematics or the examples of numerical related programming in c languages properly ... i was trying to follow these two instead ... for some understanding of the overall mathematics , before trying to do programming ... http://www.universityofcalicut.info/SDE/BSc_maths_numerical_methods.pdf for programming some maths related things , i would recommend this book ... Computer Fundamentals and Programming in C - J.B. Dixit even those books are still lacking many needed information's ... which is why i am using pictures nowadays to learn it properly ... let me arrange some things properly in this thread ... so you too know , how it looked like .. and where it is heading to ... well it begins with something like this ... http://www.mathsisfun.com/algebra/systems-linear-equations.html http://www.ce.utexas.edu/prof/mckinney/ce311k/Overheads/12-LinEqs_Direct.pdf http://www.ce.utexas.edu/prof/mckinney/ce311k/Overheads/13-LinEqs_Indirect.pdf http://www.ce.utexas.edu/prof/mckinney/ce311k/Overheads/14-NonlinearEquations_1_FixedPoint.pdf http://www.ce.utexas.edu/prof/mckinney/ce311k/Overheads/14-NonlinearEquations_2_Bisection.pdf http://www.ce.utexas.edu/prof/mckinney/ce311k/Overheads/14-NonlinearEquations_3_Newton.pdf http://www.sosmath.com/soe/SE211105/SE211105.html Differential equations ... at this point of time i am not sure how the alphabets , variables , arrays ... etc ... f(x) ... theta , d^2y/dx^2 , (dy/dx)^3 , integral symbol... are declared ... again if you use the numerical methods or the appropriate algorithm for the differential equations properly ... you should be able to find the solution of the problem with a programming language like c .. my question is , what does numerical method achieve for each one these types of numerical method questions?? because the questions ranges from ... polynomials trigonometric transcendental differentiation integration differential equations i know for a polynomial ... the numerical method means ... for differentiation and differential equations ... its about the instantaneous rate of change of the variable x with respect to y then what happens , when you apply numerical methods on their solutions ?? what does this approximate values represent ?? again is it about the instantaneous rate of change of the variable x with respect to y ... is it always about how close to zero you want the solutions to be ??