how to change variations for controlling speed/angle of Nema23 stepper motor

Hi, I wish to change speed/angle of Nema 23 stepper motor.
Below is arduino sketch, and it is working good. but I’d like to make it faster and test different rotational angle.

Source reference : HY-DIV268N nema17 - YouTube

// include stepper library
#include <Stepper.h>

const int stepsPerRevolution = 200; // Nema17 motor has 200 steps in 360 degrees rotation

// initialize the stepper library on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11); // pins 8,9 go to PULL+ & PULL- , pins 10,11 go to DIR+ & DIR-

int tracknumber = 2; // SET HOW MANY TRACKS YOU WANT UP AND BACK
int trackdistance = 20000;

int actualtracknumber = 0; // current track number

int motiondirection = 2; // set initial forward motor increments.
int forwardsincrement = 2; // forward
int backwardsincrement = -2; // backwards

int moves = 0; // current move number
int goforit = 1; // start or stop the move ?

int topspeed = 3201; // TOP SPEED OF TRACKING
int bottomspeed = 1; // start and end speed of RAMP up/down

int benspeed = 1; // current speed

void setup() {

// do some setup here

}

void loop() {

if (goforit == 1)
{
moveit();
}

else
{
donothing();
}
}

void moveit()

{

int x = 1;
for (int i = 50; i > -1; i = i + x ) {

if (i >= topspeed)
{
topspeedhold(); // hold top speed for trackdistance variable
x = -1; // switch direction at peak
}

if (i <= bottomspeed)
{
x = +1; // switch direction at troff
moves++;
actualtracknumber++;
}

int benspeed=i;
myStepper.setSpeed(benspeed);
myStepper.step(motiondirection);

if (moves >=1) motiondirection = backwardsincrement; // switch direction
if (moves >=2) motiondirection = forwardsincrement , moves = 0;
if (actualtracknumber >= tracknumber * 2 ) // when the motor has done forward and back the TRACKNUMBER amount set then back to void();
{
goforit = 0;
return;
}
}
}

void topspeedhold() // hold top speed for trackdistance variable
{
int f = 1;
for (int f = 50; f > -1; f = f + 1 ) {

if (f >= trackdistance)
{
return;
}

myStepper.setSpeed(topspeed);
myStepper.step(motiondirection);
}
}

void donothing()
{
while(1);
}

int trackdistance = 20000;
int topspeed = 3201;  // TOP SPEED OF TRACKING

oniudranij:
Hi, I wish to change speed/angle of Nema 23 stepper motor.

You need to tell us what stepper motor driver you are using.

Almost certainly it is one that takes step and direction inputs which means that the standard stepper library is not suitable. Use the AccelStepper library with its DRIVER option. Or just write your own code - have a look at this Simple Stepper Code

...R
Stepper Motor Basics