I used Statsoft software "Statistica" for the prediction of some parameters. It give values which can be use to deduce an expression. For the values of R, mse or others etc, i mostly use microsoft excel, which is very good in computing such values..

Dear Ajay, actually there is not any predefined relationship between input and output vector that is why we provide training data to learn that relationship.

You can define each and every parameter that is the beauty of programming so you think first what parameters you are going to consider e.g. which transfer function you will use. what bias you will use? what would be your initial weights? how many hidden layers you want to consider? Which learning algorithm you will use? Once you are done with all that's it. you have defined your ANN. Just calculate RMSE using input at input layer and output at output layer in each iteration. Similarly you can print intermediate values using the adjusted weights in every epoch.

Hope this will help 

Ankur Sir, Thank You very much for your valuable guidance. As per your directions, I have framed and trained my network for curve fitting. I have calculated the error (target-output) which comes under acceptable range. I am feeling difficulty to know RMSE at each epoch and to determine a mathematical relation between input and output. I am attaching my code in the message(though input and output values have been changed for better visibility). Please help (by an example if possible).

You can try NETLAB implementation if you are using MATLAB. The coding is straightforward to output specific process result during or after the network is trained. 

Best part is this toolbox is in public domain, easily understandable. 

Dear Ajay,

Please refer to Matlab's Neural Network Toolbox.

Good luck!

Luiza

Thank you friends for your answer.

I got the solution to the problem. I have coded the entire problem without using any inbuilt function of NN. I got updated weights and using them along with used function will give my mathematical expression.

Dear Ajay,

How can I get neural network mathematical expression after I have done my modeling by nftool in Matlab 2015?

I would appreciate any help.

dear Ajay

i have same problem How can I get mathematical expression of input and target in artificial neural network by matlab 2015 can u help me .

Ajay Goyal I am using MATLAB in extracting the model but the predictions which I got from using ANN equation are different from what I got when I run the model? do you have any idea about this? Please find attached screenshots of the predictions with running the ANN and using the equation.

I added the exponential to the output y because I am using Log transform.