Meeting 15 Introduction to Numerical Methods Error Analysis
Numerical Methods Numerical methods are techniques by which mathematical problems are formulated so that they can be solved with arithmetic operations.
Why We should Study Numerical Methods 1. Numerical methods are extremely powerful problem-solving tools. 2. Numerical methods provide a vehicle to reinforce the understanding of mathematics.
Significant Digit The significant digits of a number are those that can be used with confidence. They correspond to the number of certain digits plus one estimated digit. Zeros are not always significant figures because they may be necessary just to locate a decimal point.
Significant Digit The numbers , , and all have four significant figures. When trailing zeros are used in large numbers, it is not clear how many, if any, of the zeros are significant.
Significant Digit
ACCURACY AND PRECISION Accuracy refers to how closely a computed or measured value agrees with the true value. Precision refers to how closely individual computed or measured values agree with each other.
(a)inaccurate and imprecise (b) accurate and imprecise (c) inaccurate and precise (d) accurate and precise.
ERROR DEFINITIONS Numerical errors arise from the use of approximations to represent exact mathematical operations and quantities. Truncation errors -> which result when approximations are used to represent exact mathematical procedures. Round-off errors -> which result when numbers having limited significant figures are used to represent exact numbers.
ERROR DEFINITIONS