TD_​DFFT

At its core, this function takes a logical-runtime series - time series or spatial series - as an input and transforms the series from the time or spatial domain to the temporal frequency or spatial frequency domain, respectively. The input logical-runtime series can contain elements which are either real numbers PAYLOAD(CONTENT(REAL) | CONTENT(MULTIVAR_REAL)) or complex numbers PAYLOAD(CONTENT(COMPLEX) | CONTENT(MULTIVAR_COMPLEX)). The result series is always a multivariate series containing Fourier coefficients, whose elements are either complex numbers with real and imaginary components - OUTPUT_FMT(CONTENT(COMPLEX) | CONTENT(MULTIVAR_COMPLEX)); or, alternatively, whose elements consist of amplitude and phase number pairs - OUTPUT_FMT(CONTENT(AMPL_PHASE_DEGREES) | CONTENT(AMPL_PHASE_RADIANS) | CONTENT(AMPL_PHASE) | CONTENT(MULTIVAR_AMPL_PHASE_DEGREES) | CONTENT(MULTIVAR_AMPL_PHASE_RADIANS) | CONTENT(MULTIVAR_AMPL_PHASE) ). The default index of this output series is integer-based. It starts at the negative Nyquist frequency (-N/2) and goes up to the positive Nyquist frequency (N/2). Other choices for output indexes are also available to the user.

Options

ALGORITHM

Optional Parameter. Bypasses the internal DFFT Planner and influences the core DFFT algorithm associated with the primary DFFT calculation. Choices are: 'COOLEY_TUKEY', or 'SINGLETON'. When this parameter is NOT PRESENT. The internal DFFT 'Planner' will select the most efficient algorithm for the operation.

FREQ_STYLE

Optional Parameter. Determines format/values associated with the x-axis of the output. Choices are: 'K_INTEGRAL', an integer representation.; 'K_SAMPLE_RATE': normalized to 'Number Entries', ranges from -0.5 to +0.5; 'K_RADIANS', ranges from -PI to +PI; and, 'K_HERTZ', must be used in conjunction with the 'HERTZ_SAMPLE_RATE', this represents the frequency in hertz. The Default is 'K_INTEGRAL'.

HERTZ_SAMPLE_RATE

Optional Parameter. Only valid with a FREQ_STYLE(K_HERTZ). A Floating point constant representing the sample rate, in hertz. A value of 10000.0 means that the sample points were obtained by sampling at a rate of 10,000 hertz.

HUMAN_READABLE

Optional Parameter. Determines whether the produced output rows are in a human-readable / plottable form; or if they are output in the raw-form, which is equivalent to how the 'R' and 'PYTHON' programs would output the results. A value of '1' means true, output in human readable form; a value of '0' means false, output in raw form. Default is true – output in Human Readable format.

OutputFormat

The OUTPUT_FMT (CONTENT()) construct can be used by the data scientist to choose how they would like their Fourier coefficients to be output. The can use CONTENT(COMPLEX) or CONTENT(MULTIVAR_COMPLEX) to request the Fourier coefficients in rectangular form. Alternatively, they can use CONTENT(AMPL_PHASE_RADIANS), CONTENT(AMPL_PHASE_DEGREES), CONTENT(AMPL_PHASE), CONTENT(MULTIVAR_AMPL_PHASE_RADIANS), CONTENT(MULTIVAR_AMPL_PHASE), or CONTENT(MULTIVAR_AMPL_PHASE_DEGREES) to request that the Fourier coefficients be output in the polar form; and to further request the phase to be output in radians or degrees. AMPL_PHASE is one of the permitted values, it is synonymous with AMPL_PHASE_RADIANS. Similarly MULTIVAR_AMPL_PHASE is equivalent to MULTIVAR_AMPL_PHASE_RADIANS.The default value is dependent on the datatype of the input series; a single var input will generate COMPLEX output CONTENT by default; a multi var input will generate MULTIVAR_COMPLEX output CONTENT by default.

Output Schema

Output Schema, if Volatile is true then use user login as the schema.

Output Table

Output Table

VAL Location

VAL Location

Volatile

Specifies whether the table should be a VOLATILE table. If true, then the table is automatically deleted, otherwise it is users responsibility to remove or clean it up for space.

ZERO_PADDING_OK

Optional Parameter. Determines whether it is OK to add zeros to the end of a given Series to achieve a more efficient computation of the FFT coefficients. A value of '1' means true; a value of '0' means false. Default is true.

Nodes

• String Configuration4 ×
• Single Selection Configuration3 ×
• Integer Configuration2 ×
• Python Script2 ×
• Boolean Configuration1 ×
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Extensions

• FeatureKNIME Base nodes
• FeatureKNIME Database
• FeatureKNIME Quick Forms

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