## Error messages

Error 01: An error occurred while evaluating power function.

This error occurs when a number raised to the power of another number resulted in an error. For example (-4)^(-5.1) gives an error, because a negative number cannot be raised to a negative non integer number when calculating with real numbers.

Error 02: Tangent to pi/2+n*pi (90°+n180° in degrees) is undefined.

tan(x) is undefined for x= π/2+πp = 90°+p180°, where p is an integer.

Error 03: Fact can only be calculated for positive integers.

fact(x), which calculates the factorial number of x, is only defined for positive integers of x.

Error 04: Cannot take logarithm to number equal or less than zero.

The logarithmic functions ln(x) and log(x) are undefined for x0, when the calculation is done for real numbers. When the calculations are done with complex numbers, x is only undefined at 0.

Error 05: sqrt is undefined for negative numbers.

sqrt(x) is undefined for x<0, when the calculations are done for real numbers. sqrt(x) is defined for all numbers, when the calculations are done with complex numbers.

Error 06: A part of the evaluation gave a number with an imaginary part.

This error may occur when calculations are done with real numbers. If a part of the calculation resulted in a number with an imaginary part, the calculation cannot continue. An example of this is: sin(x+i)

Error 07: Division by zero.

The program tried to divide by zero when calculating. A function is undefined for values where a division by zero is needed. For example the function f(x)=1/x is undefined at x=0.

Error 08: Inverse trigonometric function out of range [-1;1]

The inverse trigonometric functions asin(x) and acos(x) are only defined in the range [-1;1], and they are not defined for any numbers with an imaginary part. The function atan(x) is defined for all numbers without an imaginary part. This error may also happen if you are trying to take arg(0).

Error 09: The function is not defined for this value.

This error may occur for functions that are not defined for a specific point. This is for example the case for sign(x) and u(x) at x=0.

Error 10: atanh evaluated at undefined value.

Inverse hyperbolic tangent atanh(x) is undefined at x=1 and x=-1, and not defined outside the interval x=]-1;1[ when calculating with real numbers only.

Error 11: acosh evaluated at undefined value.

Inverse hyperbolic cosine acosh(x) is only defined for x1 when using real numbers. acosh(x) is defined for all numbers when calculating with complex numbers.

Error 12: arg(0) is undefined.

The argument of zero is undefined because 0 does not have an angle.

Error 13: Evaluation failed.

This error occurs when a more complicated function like W(z) is evaluated, and the evaluation failed to find an accurate result.

Error 14: Argument produced a function result with total loss of precision.

An argument to a function call produced a result with total loss of significant digits, such as sin(1E70) which gives an arbitrary number in the range [-1;1].

Error 15: The custom function/constant '%s' was not found or has the wrong number of arguments.

A custom function or constant no longer exists. You can either define it again or remove all uses of the symbol. This may also happen if a custom constant has been changed to a function or vice versa, or if the number of arguments to a custom function has been changed.

Error 16: Too many recursive calls

Too many recursive calls have been executed. This is most likely caused by a function that calls itself recursively an infinite number of times, for example foo(x)=2*foo(x). The error may also occur if you just call too many functions recursively.

Error 17: Overflow: A function returned a value too large to handle.

A function call resulted in value too large to handle. This for example happens if you try to evaluate sinh(20000)

Error 18: A plugin function failed.

A custom function in a Python plugin did not return a result. The Python interpreter window may show more detailed information.

Error 50: Unexpected operator. Operator %s cannot be placed here

An operator +, -, *, / or ^ was misplaced. This can happen if you try entering the function f(x)=^2, and it usually means that you forgot something in front of the operator.

Error 55: Right bracket missing.

A right bracket is missing. Make sure you have the same number of left and right brackets.

Error 56: Invalid number of arguments supplied for the function '%s'

You passed a wrong number of arguments to the specified function. Check the List of functions to find the required number of arguments the function needs. This error may occur if you for example write sin(x,3).

Error 57: Comparison operator misplaced.

Only two comparison operators in sequence are allowed. For example "sin(x) < y < cos(x)" is okay while "sin(x) < x < y < cos(x)" is invalid because there are three <-operators in sequence.

Error 58: Invalid number found. Use the format: -5.475E-8

Something that looked like a number but wasn't has been found. For example this is an invalid number: 4.5E. A number should be on the form nnn.fffEeee where nnn is the whole number part that may be negative. fff is the fraction part that is separated from the integer part with a dot '.'. The fraction part is optional, but either the integer part or the fraction part must be there. E is the exponent separator and must be an 'E' in upper case. eee is the exponent optionally preceded by '-'. The exponent is only needed if the E is there. Notice that 5E8 is the same as 5*10^8. Here are some examples of numbers: `-5.475E-8, -0.55, .75, 23E4`

Error 59: String is empty. You need to enter a formula.

You didn't enter anything in the box. This is not allowed. You need to enter an expression.

Error 60: Comma is not allowed here. Use dot as decimal separator.

Commas may not be used as decimal separator. You have to use a '.' to separate the fraction from the integer part.

Error 61: Unexpected right bracket.

A right bracket was found unexpectedly. Make sure the number of left and right brackets match.

Error 63: Number, constant or function expected.

A factor, which may be a number, constant, variable or function, was expected.

Error 64: Parameter after constant or variable not allowed.

Brackets may not be placed after a constant or variable. For example this is invalid: f(x)=x(5). Use f(x)=x*5 instead.

Error 65: Expression expected.

An expression was expected. This may happen if you have empty brackets: f(x)=sin()

Error 66: Unknown variable, function or constant: %s

You entered something that looks like a variable, function or constant but is unknown. Note that "x5" is not the same as "x*5".

Error 67: Unknown character: %s

An unknown character was found.

Error 68: The end of the expression was unexpected.

The end of the expression was found unexpectedly.

Error 70: Error parsing expression

An error happened while parsing the function text. The string is not a valid function.

Error 71: A calculation resulted in an overflow.

An overflow occurred under the calculation. This may happen when the numbers get too big.

Error 73: An invalid value was used in the calculation.

An invalid value was used as data for the calculation.

Error 74: Not enough points for calculation.

Not enough data points were provided to calculate the trendline. A polynomial needs at least one more point than the degree of the polynomial. A polynomial of third degree needs at least 4 points. All other functions need at least two points.

Error 75: Illegal name %s for user defined function or constant.

Names for user defined functions and constants must start with a letter and only contain letters and decimal digits. You cannot use names that are already used by built-in functions and constants.

Error 76: Cannot differentiate recursive function.

It is not possible to differentiate a recursive function because the resulting function will be infinitely large.

Error 79: Function %s cannot be differentiated.

The function cannot be differentiated, because some part of the function does not have a first derivative. This is for example the case for arg(x), conj(x), re(x) and im(x).

Error 86: Not further specified error occurred under calculation.

An error occurred while calculating. The exact cause is unknown. If you get this error, you may try to contact the programmer with a description of how to reproduce the error. Then he might be able to improve the error message or prevent the error from occurring.

Error 87: No solution found. Try another guess or another model.

The given guess, which may be the default one, did not give any solution. This can be caused by a bad guess, and a better guess may result in a solution. It can also be because the given trendline model doesn't fit the data, in which case you should try another model.

Error 88: No result found.

No valid result exist. This may for example happen when trying to create a trendline from a point series where it is not possible to calculate a trendline. One reason can be that one of the calculated constants needs to be infinite.

Error 89: An accurate result cannot be found.

Graph could not calculate an accurate result. This may happen when calculating the numerical integral produced a result with a too high estimated error.

Error 99: Internal error. Please notify the programmer with as much information as possible.

An internal error happened. This means that the program has done something that is impossible but happened anyway. Please contact the programmer with as much information as necessary to reproduce the problem.